s = 1
def giaithua(n):
    global s
    for i in range (1, n+1):
        s=s*i
    return s

#print("Nhap n: ")
n=int(input("Nhap n: "))
#print(n, "! =", giaithua(n))
#print("%d! = %d" %(n, giaithua(n)))
print("{0}! = {1}".format(n, giaithua(n)))