1
#include <bits/stdc++.h>
2
#define ll long long
3
 
4
using namespace std;
5
 
6
int main() {
7
    std::ios_base::sync_with_stdio(false);
8
    cin.tie(0);
9
    cout.tie(0);
10
    int n, m;
11
    cin >> n >> m;
12
    int dp[n + 1][m + 1] = {};
13
    dp[1][1] = 1;
14
    for (int i = 2; i <= m; ++i) {
15
        dp[1][i] = dp[1][i - 1];
16
    }
17
    
18
    for (int i = 2; i <= n; ++i) {
19
        dp[i][1] = dp[i - 1][1];
20
    }
21
    
22
    for (int i = 2; i <= n; ++i) {
23
        for (int j = 2; j <= m; ++j) {
24
            dp[i][j] = dp[i - 1][j] + dp[i][j - 1];
25
        }
26
    }
27
    
28
    cout << dp[n][m];
29
    return 0;
30
}
31
 
32
 
33