#include <bits/stdc++.h>
//#include <boost/multiprecision/cpp_int.hpp>
//#define bigint boost::multiprecision::cpp_int
#define ll unsigned long long int
#define pii pair<int,int>
#define pll pair<ll,ll>
#define pb push_back
#define mp make_pair
#define gcd __gcd
#define bs binary_search
#define itr vector <int> :: iterator
#define beg v.begin(), v.end()
#define vi vector <int> 
#define lb lower_bound
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define tt int t; cin>>t; while(t--)
#define ff first
#define ss second
#define fora(i,a,b) for(i=a;i<b;i++)
#define reva(i,a,b) for(i=a;i>=b;i--)
using namespace std;

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