import sys


def input(): return sys.stdin.readline().rstrip('\n')


def main():
    a = 1
    n = int(input())
    ov = False
    for i in range(1, n+1):
        a = a*i
        if a >= 10**12:
            ov = True
            a %= 10**12
        if a == 0:
            break

    if ov:
        print(f'{a:012}')
    else:
        print(a)


if __name__ == '__main__':
    main()