#include <bits/stdc++.h>
#define ll long long int
#define PB push_back
#define ld long double
#define MP make_pair
#define F first
#define S second
#define sd(x) scanf("%d",&x)

using namespace std;

int main() {
    ll n,m;
    cin>>n>>m;
    ll ans = (m-1);
    ans+= (ll)(n-1LL)*(ll)m;
    cout<<ans<<endl;
    return 0;
}