package Practice;

import java.io.BufferedReader;

import java.io.InputStreamReader;

import java.math.BigInteger;

import java.util.StringTokenizer;

public class B2407 { //Á¶ÇÕ

public static void main(String args[]) throws Exception {

BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

StringTokenizer st = new StringTokenizer(br.readLine());

int N = Integer.parseInt(st.nextToken()), M = Integer.parseInt(st.nextToken());

BigInteger[][] dp = new BigInteger[101][101];

for(int i = 0; i <= 100; i++) {

for(int j = 0 ; j <= 100; j++) dp[i][j] = new BigInteger("0");

}

for(int i = 0; i <= 100; i++) {

dp[i][0] = BigInteger.valueOf(1);

dp[i][i] = BigInteger.valueOf(1);

}

for(int i = 2; i <= 100; i++) {

for(int j = 1; j < i; j++) dp[i][j] = dp[i - 1][j].multiply(BigInteger.valueOf(i)).divide(BigInteger.valueOf(i - j));

}

System.out.println(dp[N][M]);

}

}