#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>
#include <climits>
#include <algorithm>
#include <numeric>
#include <string>
#include <vector>
#include <map>
#include <unordered_map>
#include <queue>

using namespace std;

typedef long long int64;
typedef pair<int, int> intp;

int64 n, m, ans;

int main() {
    cin >> n >> m;
    if (n < m)
        swap(n, m);
    ans = (n-1)+n*(m-1);
    cout << ans << endl;

    return 0;
}