#include <map>
#include <set>
#include <list>
#include <cmath>
#include <ctime>
#include <deque>
#include <queue>
#include <stack>
#include <string>
#include <bitset>
#include <cstdio>
#include <limits>
#include <vector>
#include <climits>
#include <cstring>
#include <cstdlib>
#include <fstream>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <unordered_map>

using namespace std;


int main() {
    int n;
    int m;
    cin >> n >> m;
    
    if(n == 1)
        cout << (m-1);    
    else if(m == 1)
        cout << (n-1);
    else    
        cout << (n-1) + n * (m-1);
    
    return 0;
}