//OUM HARI OUM, OUM TATSAT
// OUM NAMA VAGABATE BASUDEBAY
// OUM NAMA MA SWARASATI OUM NAMA

#include<cmath>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<cctype>
#include<fstream>
#include<string>
#include<vector>
#include<queue>
#include<map>
#include<set>
#include<sstream>
#include<stack>
#include<stdlib.h>
#include<iostream>
#include<algorithm>

#define sc1(a) scanf("%d",&a)
#define sc2(a,b) scanf("%d %d",&a,&b)
#define sc3(a,b,c) scanf("%d %d %d",&a,&b,&c)
#define scd1(a) scanf("%lf",&a)
#define scd2(a,b) scanf("%lf %lf",&a,&b)
#define scd3(a,b,c) scanf("%lf %lf %lf",&a,&b,&c)
#define scl1(a) scanf("%lld",&a)
#define scl2(a,b) scanf("%lld %lld",&a,&b)
#define scl3(a,b,c) scanf("%lld %lld %lld",&a,&b,&c)

#define cl(vctr) vctr.clear()
#define ms(v, ar) memset(ar, v, sizeof(ar))

const double pi=(double)(2.0 * acos( 0.0 ));
const int inf=1 << 30;
const double eps=1E-9;
const double e = exp(1.0);
const int sz=100000 + 5;

using namespace std;
typedef long long int ll;
const ll mod=1000000000 + 7;

int main()
{
    ll n,m;
    scl2(n,m);
    printf("%lld\n",n-1+n*(m-1));

    return 0;
}