#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
typedef int64_t ll;
ll max(ll a,ll b)
    {
    if(a>b)
        return a;
    else
        return b;
}
int main() {
    ll a,b;
    cin>>a>>b;
   ll sum=(max(a,b)-1)*min(a,b)+min(a,b)-1;
    cout<<sum<<"\n";
    return 0;
}