20254026
# n,m,k = map(int,input().split())
# d = [[0]*(1001) for i in range(1001)]
# x = []
# c = []
# t = 0
# result = []
# for i in range(k):
# a = []
# a = list(map(int,input().split()))
# x.append(a)
# for i in range(k):
# d[x[i][0]][x[i][1]] += x[i][4]
# d[x[i][2]+1][x[i][3]+1] += x[i][4]
# d[x[i][0]][x[i][3]+1] -= x[i][4]
# d[x[i][2]+1][x[i][1]] -= x[i][4]
# for i in range(n):
# print(" ".join(map(str, d[i][:m])))
# print()
# for i in range(n):
# for j in range(1,m):
# d[i][j] += d[i][j-1]
# for i in range(m):
# for j in range(1,n):
# d[j][i] += d[j-1][i]
# for i in range(n):
# print(" ".join(map(str, d[i][:m])))
x = []
q = [[0]*100 for i in range(100)]
w = 0
for i in range(4):
a = list(map(int,input().split()))
x.append(a)
a = []
for i in range(4):
if x[i][0] >= x[i][2]:
s1 = x[i][2]
else:
s1 = x[i][0]
if x[i][1] >= x[i][3]:
s2 = x[i][3]
else:
s2 = x[i][1]
for j in range(s1,abs(x[i][0]+x[i][2]):
for j in range(s1,abs(x[i][0]+x[i][2]):
for i in range(100):
w += q[i].count(1)
print(w)