#include<bits/stdc++.h>
#define boost ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#define pb push_back
#define mp make_pair
#define ll long long int
#define M 1000000007
#define PI 3.14159265
using namespace std;

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