#include <bits/stdc++.h>
#define _kiet int main ()
#define ll long long
#define str string
#define fir first
#define sec second
#define ld long double
#define pb push_back
#define MOD 100000009
#define freopen(name) if(fopen(name".INP","r")) {freopen (name".INP","r",stdin); freopen (name".OUT","w",stdout);}
#define ALL(x) (x).begin(),(x).end()
using namespace std;
int solve(int m, int n)
{
    if (m <= 0 || n <= 0)
        return 0;
    vector<vector<int>> a(m + 1, vector<int>(n + 1, 0));
    for (int i = 1; i <= m; i++) {
        for (int j = 1; j <= n; j++) {
            if (i >= 2 && j >= 1) {
                a[i][j] = max(a[i - 1][j], a[i][j - 1]) + 1;
            } else {
                a[i][j] = 0;
            }
        }
    }
    return a[m][n];
}
_kiet
{
//
    int m, n;
    cin >> m >> n;
    int res = solve(m, n);
    cout << res << endl;
    return 0;
}

$#lamtung$