import java.io.*; import java.util.*; public class Main{ public static void main(String[] args) throws Exception{ Scanner sc = new Scanner(System.in); while(sc.hasNext()){ int n = sc.nextInt(); int m = sc.nextInt(); int[][] dp = new int[n + 1][m + 1]; for(int i = 0; i <= n; ++i){ for(int j = 0; j <= m ; ++j){ if(i == 0 || j == 0){ dp[i][j] = 1; }else{ dp[i][j] = dp[i][j - 1] + dp[i - 1][j]; } } } System.out.println(dp[n][m]); } } }