N = int(input())
mod = 1000000000000
ans = 1
f = False
for i in range(1,N+1):
    ans *= i
    if f==False and (ans //mod >= 1):
        f = True
    ans %= mod
    if ans == 0:
        break
if f:
    l = str(ans)
    print('0'*(12-len(l))+str(ans))
else:
    print(ans)