#206 백준 파이썬 [2407] 조합

https://www.acmicpc.net/problem/2407

 

#Solution

n, m = map(int, input().split())
answer = 1
k = n - m

while n > k:
    answer *= n
    n -= 1
while m > 1:
    answer = answer // m
    m -= 1

print(answer)