#include <bits/stdc++.h>

using namespace std;

int main( int argc , char * argv[] ){
	int n , m ;
	cin >> n >> m;
	long long ret = min( n - 1 + 1LL * n * (m - 1) , m - 1 + 1LL * m * (n - 1) );
	cout << ret << endl;
	return 0;
}