MOD = 10 ** 12
n = int(input())

fact = 1
is_overflown = False
for i in range(n):
    j = i + 1
    if fact == 0:
        break
    if fact * j >= MOD:
        is_overflown = True
    fact *= j
    fact %= MOD

if not is_overflown:
    print(fact)
else:
    print("{0:012d}".format(fact))