#include <iostream>
#include <cmath>
#include <algorithm>
#include <vector>
#include <cstring>
#include <deque>
#include <stack>
#include <stdio.h>
#include <map>
#include <set>
#include <time.h>
#include <string>
#include <fstream>
#include <queue>
#include <bitset>
#include <cstdlib>
#define X first
#define Y second
#define mp make_pair
#define pb push_back
#define pdd pair<double,double>
#define pii pair<ll,ll>
#define PI 3.14159265358979323846
#define MOD 1000000007
#define MOD2 1000000009
#define INF ((ll)1e+18)
#define x1 fldgjdflgjhrthrl
#define x2 fldgjdflgrtyrtyjl
#define y1 fldggfhfghjdflgjl
#define y2 ffgfldgjdflgjl
#define N 202100
#define SUM 23423
#define MAG 333
typedef long long ll;
typedef long double ld;
using namespace std;
ll i,j,n,k,l,m,x,y,tot, flag,h,r,ans,koko,z,nl,nr;
ll a[100500], b[100500], used[100500];
ll Abs(ll x)
{
	return x>0?x:-x;
}
int main() {
	//freopen("input.txt","r",stdin);
	//freopen("output.txt","w",stdout);
	cin >> n >> m;
	cout << m*n-1 << endl;
	return 0;
}