def main():
    import sys
    input = sys.stdin.readline

    mod = 10**12
    ans = 1
    N = int(input())
    for i in range(1, N+1):
        ans = (ans * i)%mod
        if ans == 0:
            print('0' * 12)
            exit()
    print(ans)


if __name__ == '__main__':
    main()