d | 특수목적코딩학원 광교본점

# a,b,c = map(int,input().split())
# v = 1
# while not (v%a==0 and v%b==0 and v%c==0) :
#     v+=1
# print(v)

# import copy
#
# data = list(map(int,input().split()))
#
# a = copy.deepcopy(data)
#
# data.clear()
#
# print(a)

# for i in range(len(data)) :
#     print(data[i])

# for x in data :
#     print(x)


'''a = [1,3,4,7,4,5,1]

print(sum(a))
print(max(a))
print(min(a))
print(len(a))

a.sort()
print(a)

a.reverse()
print(a)

a.append(12)
print(a)

a.insert(2,100)
print(a)

a.pop()
print(a)

b = a.pop()
print(b)
print(a)

a.pop(3)        #3번째 데이터 삭제
print(a)

a.append(4)
a.append(4)

print(a)
print(a.count(4))

print(a.index(50))  # 50의 위치 리턴

a.remove(7)         #7값을 찾아서 삭제
a = int(input())
b = list(map(int,input().split()))
for i in range(1,24,1) :
    print(b.count(i),end=' ')'''
# a = int(input())
# b = list(map(int,input().split()))
# b.reverse()
# for i in range(0,len(b),1) :
#     print(b[i],end=' ')
# a = int(input())
# b = list(map(int,input().split()))
# print(min(b))
# a = int(input())
# for i in range(5):
#


# a = [ [0 for i in range(10)] for j in range(10) ]
# print(a)

# 가로 w, 세로 h인 이차원 배열 만들기
# a = []
# w, h = 10,10
# for i in range(h) :
#     a.append(list(map(int,input().split())))
#     # a.append([0]*w)
#
# print(a)
# a[0][0] = 10
#
# print(a)

# a = [[0 for i in range(20)] for j in range(20)]
# b = int(input())
# for i in range(b) :
#     c = list(map(int,input().split()))
#     a[c[0]][c[1]] = 1
# for i in range(1,20):
#     for j in range(1,20):
#         print(a[i][j],end='')
#         if j!=19 :
#             print(' ',end='')
#     if(i==19):
#         print('',end='')
#     else:
#         print('')
# a = []
# w,h = 20,20
# for i in range(0,19):
#     a.append(list(map(int,input().split())))
# x = int(input())
# for i in range(x):
#     c = list(map(int,input().split()))
#     for j in range(0,19):
#         if not j==c[0]-1:
#             a[j][c[1]-1] = int(not a[j][c[1]-1])
#         if not j==c[1]-1:
#             a[c[0]-1][j] = int(not a[c[0]-1][j])
# for i in range(0,19):
#     for j in range(0,19):
#         print(a[i][j],end='')
#         if j!=18:
#             print(' ',end='')
#     if i != 18:
#         print('')
# y,x = map(int,input().split())
# a = [[0 for i in range(x)] for j in range(y)]
# c = int(input())
# for i in range(c):
#     v = list(map(int,input().split()))
#     v[3] -= 1
#     v[2] -= 1
#     for j in range(v[0]):
#         if v[1]==0:
#             #if j + v[3] > x-1:
#             #    break
#             a[v[2]][j + v[3]] = 1
#         else :
#             #if j + v[2] > y-1:
#             #    break
#             a[j + v[2]][v[3]] = 1
# for i in range(y):
#     for j in range(x):
#         print(a[i][j],end = '')
#         if j != x-1:
#             print(' ',end='')
#     if i != y-1:
#         print('')
# a = []
# for i in range(10):
#     a.append(list(map(int,input().split())))
# x = 1
# y = 1
# while 1 :
#     if a[y][x]==2 :
#         a[y][x]=9
#         break
#     a[y][x] = 9
#     if a[y][x+1]!=1:
#         x += 1
#     elif a[y][x+1]==1 and a[y+1][x]!=1:
#         y+=1
#     else :
#         break
# for i in range(10):
#     for j in range(10):
#         print(a[i][j],end='')
#         if j!=9:
#             print(' ',end='')
#     if i != 9:
#         print('')

# # 이차원배열 정렬
# a = [ [1,3] , [3,2] , [2,7] ]
# a.sort(key = lambda x : -x[1])
# print(a)
#
# a = []
# 1805
# 3015
# 3019
# 3108
# a = int(input())
# b= []
# for i in range(a):
#     b.append(list(map(int,input().split())))
# b.sort(key= lambda x : x[0])
# for i in range(a):
#     print(b[i][0],b[i][1])
# a,b = map(int,input().split())
# c = []
# for i in range(a):
#     c.append(list(input().split()))
#     c[i][1] = int(c[i][1])
# c.sort(key= lambda x : -x[1])
# for i in range(b):
#     print(c[i][0])
# a = list(map(int,input('').split()))
# print(a)

# a = list(input())
# print(a)
# a = list(map(int, a))
# print(a)

# 스택 stack :  쌓는거, 나중에들어온게 먼저나가는 구조, 후입선출 -> Last In First Out -> LIFO

# st = []
#
# st.append("hello")
# st.pop()
# top -> len(st)-1

# stack의 구조 활용 문제
# 1. 3117 2016 3102 -> 스택연습
# 2. 3127 3130 -> 리얼 스택 활용
# a = []
# c = 0
# x = int(input())
# for i in range(x):
#     n = int(input())
#     if n!=0:
#         a.append(n)
#     else:
#         a.pop()
# for i in range(len(a)):
#     c += a[i]
# print(c)
# a = int(input())
# x = list(map(int,input()))
# c = []
# x.reverse()
# for i in range(len(x)):
#     c.append(x[i])
#     if (i+1)%3==0 and i!= len(x)-1:
#         c.append(',')
# c.reverse()
# for i in range(len(c)):
#     print(c[i],end='')
# a = int(input())
# sk = []
# for i in range(a):
#     x = input()
#     if x == 'top()':
#         if len(sk)==0:
#             print(-1)
#             continue
#         print(sk[len(sk)-1])
#     elif x =='pop()' and len(sk) != 0:
#         sk.pop()
#     elif x == 'size()':
#         print(len(sk))
#     elif x == 'empty()' :
#         print('true' if len(sk)==0 else 'false')
#     elif x[1] =='u' :
#         sk.append(int(x[6:-2]))
#         #print(int(x[6:-2]))
# a = list(input().split())
# jsby = [] # 정수배열 jungsubaeyeol
# def ys(x): # 연산 yeonsan
#     jsby.pop()
#     jsby.pop()
#     jsby.append(x)
#
# for i in range(len(a)):
#     if a[i]=='+':
#         x = jsby[-1] + jsby[-2]
#         ys(x)
#     elif a[i]=='-':
#         x = jsby[-2] - jsby[-1]
#         ys(x)
#     elif a[i]=='*':
#         x = jsby[-1] * jsby[-2]
#         ys(x)
#     else:
#         jsby.append(int(a[i]))
#     # print(jsby[-1])
# print(jsby[0])


# 소들의 헤어스타일 1
# import sys
# sys.setrecursionlimit(78956727)
# a = int(input())
# st = []
# count = 0
# def ax (gap):
#     global st,count
#     #print(st,count)
#     if len(st) > 0 and (st[-1] <= gap or (gap == -1 and len(st) > 1 and st[-1] < st[-2])):
#         st.pop()
#         count += len(st)
#         ax(gap)
#     return
# for i in range(a):
#     x = int(input())
#     ax(x)
#     st.append(x)
# ax(-1)
# print(count)
# a = int(input())
# st = []
# count = 0
# for i in range(a):
#     if i<a:
#         x = int(input())
#     # print(st,count)
#     if i > 0 and st[-1] <= x:
#         for j in range(len(st)):
#             if st[-1] <= x:
#                 st.pop()
#             else:
#                 break
#     if len(st) > 0 and st[-1] > x:
#         count += len(st)
#     if i<a:
#         st.append(x)
# print(count)
# a = int(input())
# st = []
# wg = 0 # w(hat i lookin)g
# x = list(map(int,input().split()))
# for i in range(a):
#     if len(st)==0:
#         st.append([x[i],i])
#         print('0',end='')
#         continue
#     # print('\n asdfasdf',st[-1][0], st[-1][1], len(st), x[i])
#     while len(st)!=0 and x[i] >= st[-1][0]:
#         st.pop()
#     #print(st)
#
#     if len(st)!=0:
#         # print('asdfasdf2',st[-1][0],st[-1][1],i,x[i])
#         print('',st[-1][1]+1,end='')
#     else:
#         print(' 0',end='')
#     st.append([x[i],i])
# a = int(input())
# b = list(map(int,input().split()))
# c = int(input())
# d = list(map(int,input().split()))
# import sys
# sys.setrecursionlimit(134589730)
# def s(sp,ep,tr):
#     c = sp+((ep-sp)//2)
#     # print('check',sp,ep,tr,c,b[c])
#     if tr==b[c]:
#         return c
#     elif c==0 or c==ep:
#         return -2
#     elif tr < b[c]:
#         return s(sp,c-1,tr)
#     elif tr > b[c]:
#         return s(c+1,ep,tr)
# for i in range(c):
#     print(int(s(0,a-1,d[i]))+1,end=' ')
# a = int(input())
# k = list(map(int,input().split()))
# t = list(map(int,input().split()))
# z = [[2,1],[2,-1],[-2,1],[-2,-1],[1,2],[-1,2],[1,-2],[-1,-2]]
# maps = [[0 for i in range(1000)] for j in range(1000)]
# x = []
# k[0]-=1
# k[1]-=1
# k.append(0)
# x.append(k)
# min = -1
#
# while 1:
#     x0 = x[0][0]
#     y0 = x[0][1]
#     c = x[0][2]
#     if maps[x0][y0]==1:
#         x.pop(0)
#         continue
#     maps[x0][y0]=1
#     print([x0,y0,c],t,min)
#     if x0+1 == t[0] and y0+1 == t[1]:
#         print(c)
#         break
#     for i in range(8):
#         x1 = x0 + z[i][0]
#         y1 = y0 + z[i][1]
#         tt = t[0]+t[1]
#         if (x1 < a and x1 >= 0) and (y1 < a and y1 >= 0):
#             if ((abs((x1+y1+2)-tt) <= min or min==-1 or min < 15)):
#                 min = abs((x1+y1+2)-tt)
#                 x.append([x1,y1,c+1])
#     x.pop(0)
import sys
sys.setrecursionlimit(45867345)
n,m,k = map(int,input().split())
maps = [[0 for i in range(m)] for j in range(n)]
count = 0
t = []
def jG(pos): # jaeGuei 재귀
    #print(pos)
    gap = 0
    global n,maps
    y = pos[0]
    x = pos[1]
    maps[y][x]=1
    if y + 1 < n and maps[y+1][x]==0:
        gap += jG([y+1,x])+1
    if y - 1 >= 0 and maps[y-1][x]==0:
        gap += jG([y-1,x])+1
    if x + 1 < m and maps[y][x+1]==0:
        gap += jG([y,x+1])+1
    if x - 1 >= 0 and maps[y][x-1]==0:
        gap += jG([y,x-1])+1
    return gap

def jg(x0,y0,x1,y1): # JiksagakheongmandulGe 직사각형 만들기
    global maps
    for i in range(y0,y1):
        for j in range(x0,x1):
            maps[i][j]=1
for i in range(k):
    g,h,j,l = map(int,input().split())
    jg(g,h,j,l)
for i in range(n):
    for j in range(m):
        if maps[i][j]==0:
            count += 1
            t.append(jG([i,j])+1)
print(count)
t.sort()
for i in range(len(t)):
    print(t[i],end=' ')