250905

# def f(k, p):
#     global memo
#     if memo[k][p]!=0:
#         return memo[k][p]
#
#     if k==1 or p==1:
#         memo[k][p]=1
#         return memo[k][p]
#
#     else:
#         memo[k][p]=f(k-1, p)+f(k, p-1)
#         return memo[k][p]
#
# memo=[]
# x, y=map(int, input().split())
# for i in range(1, 51):
#     b=[0]*50
#     memo.append(b)
# print(f(x, y)%100000000)

# def f(k, p):
#     h=1
#     if(arr[k][p]>h):
#
#
#
# n=int(input())
# arr=[]
# for i in range(n):
#     x=list(map(int, input().split()))
#     arr.append(x)
#
# for i in range(n):
#     for j in range(n):
#         f(i, j)

def f(cir):
    a=0
    b=0
    c=0
    for i in range(c, cir/2):
        if 


n=int(input().split())
f(n)