n = int(raw_input())
a = 1
b = 1
of = False
while b <= n and a != 0:
    a *= b
    if a >= 10**12:
        of = True
    a %= 10**12
    b += 1
if of:
    s = 12 - len(str(a))
    print '0'*s + str(a)
else:
    print a