#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;


int main() {
    long long a,b,c,d;
    cin>>c>>d;
    a=min(c,d);
    b=max(c,d);
    long long  s;
    s=a-1;
    s=s+(a)*(b-1);
    cout<<s<<endl;
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}