#include <bits/stdc++.h>
using namespace std;

#define IO ios_base::sync_with_stdio(false); cin.tie(0);
#define endl "\n"
#define DBG 666
#define mp make_pair
#define revsort(x,y) sort((x),(x+y));reverse((x),(x+y));

typedef long long ll;

int main(){

	IO;

	ll n, m;
	cin >> n >> m;
	ll res = m-1;
	res += m*(n-1);
	cout << res << endl;

	return 0;
}