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


int main() {
    long long int n=0,m=0,sum=0;
	while(scanf("%lld %lld",&n,&m)==2)
	{
		sum=0;
		sum=n*m;
		sum--;
		printf("%lld\n",sum);
	}
    return 0;
}