//Author: AKSHAY VASANDANI FROM JAYPEE INSTITUTE OF INFORMATION TECHNOLOGY
 
 
 
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define gcd __gcd
#include<bits/stdc++.h>
#define fi first
#define se second
#define mod 1000000007
#define pb push_back
#define N 100001
#define eb emplace_back
//#include <boost/multiprecision/cpp_int.hpp>
//#define bigint boost::multiprecision::cpp_int
 
using namespace std;
//using namespace __gnu_pbds;
/*typedef tree<
int,
null_type,
less<int>,
rb_tree_tag,
tree_order_statistics_node_update>
ordered_set;
 
 
ordered_set gset[100001];
*/
 
 
int readInt () {
	bool minus = false;
	int result = 0;
	char ch;
	ch = getchar();
	while (true) {
		if (ch == '-') break;
		if (ch >= '0' && ch <= '9') break;
		ch = getchar();
	}
	if (ch == '-') minus = true; else result = ch-'0';
	while (true) {
		ch = getchar();
		if (ch < '0' || ch > '9') break;
		result = result*10 + (ch - '0');
	}
	if (minus)
		return -result;
	else
		return result;
}
 
ll readLong () {
	bool minus = false;
	ll result = 0;
	char ch;
	ch = getchar();
	while (true) {
		if (ch == '-') break;
		if (ch >= '0' && ch <= '9') break;
		ch = getchar();
	}
	if (ch == '-') minus = true; else result = ch-'0';
	while (true) {
		ch = getchar();
		if (ch < '0' || ch > '9') break;
		result = result*10 + (ch - '0');
	}
	if (minus)
		return -result;
	else
		return result;
}
 
 
ll p(ll a,ll b)
{
    ll temp;
    if(b==0)
    return 1;
    temp=p(a,b/2)%mod;
    if(b&1)
    return (((a*temp)%mod)*temp)%mod;
    else
    return (temp*temp)%mod;
}
 
 
 int i,j,n,m,q,u,h,t,k,a,b,c,d;
 
 int s,de,f,e,g,cnt,l,x,y,r,mi,h1;

int ar[200001];

ll minn(ll a,ll b)
{
	if(a<=b)
	return a;
	return b;

}
int main()
{
n=readInt();
m=readInt();
    ll a1=0;
    if(n>1)
   a1=((ll)n-1);
    if(m>1)
        a1+=(ll)(m-1)*((ll)n);
    cout<<a1<<endl;

	return 0;
}