def main():

    n = int(eval(input()))

    for x in range(1, n):

        n *= x

    print(n)





if __name__ == "__main__":

    main()
n = int(eval(input()))

ans = 1

for i in range(1, n + 1):

    ans *= i

print(ans)

def main():
    n = int(eval(input()))
    for x in range(1, n):
        n *= x
    print(n)


if __name__ == "__main__":
    main()

n = int(eval(input()))
ans = 1
for i in range(1, n + 1):
    ans *= i
print(ans)

-def main(): -    n = int(eval(input())) -    for x in range(1, n): -        n *= x -    print(n) - - -if __name__ == "__main__": -    main() +n = int(eval(input())) +ans = 1 +for i in range(1, n + 1): +    ans *= i +print(ans)