题解 | #走方格的方案数#

import java.math.*;

public class Main{
    public static void main(String[] args){
        Scanner input = new Scanner(System.in);
        while(input.hasNextInt()){
            int n = input.nextInt();
            int m = input.nextInt();
            int[][] chess = new int[m][n];
            //int[8][8] chess = 
            //chess[0][0] = 1;
            for(int i = 0; i < m; i++){
                chess[i][0] = i+2;
            }
            for(int j = 0; j < n; j++){
                chess[0][j] = j+2;
            }

            if(m > 1 && n > 1){
                for(int j = 1; j < n; j++){
                    for(int i = 1; i < m; i++){
                        chess[i][j] = chess[i-1][j] + chess[i][j-1];
                    }
                }
            }
            System.out.println(chess[m-1][n-1]);
            }
        }
}