#include<bits/stdc++.h>
using namespace std;
# define ll long long int 
ll arr[1000001];
string str;
int main(){
	ios::sync_with_stdio(false);cin.clear();
	ll t,n,i,j,ans=0,count=0,sum=0,k,m;
		cin>>n>>t;
		ans=n*t-1;
		cout<<ans;
}