class HelloWorld {
  // 根据推理可得 
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n1 = in.nextInt();
        int n2 = in.nextInt();
        int[][] ss = new int[n1+1][n2+1];
        for (int i = 1; i <= n1; i++) {
            for (int j = 1; j <= n2; j++) {
                if (i == 1) {
                    ss[i][j] = j + 1;
                } else if (j == 1) {
                    ss[i][j] = i + 1;
                } else {
                    ss[i][j] = ss[i][j-1]+ss[i-1][j];
                }
            }
        }
        System.out.println(ss[n1][n2]);
    }
}