#include <stdio.h>
#include <string.h>
#include <math.h>
#include <stdlib.h>

int main() {

    /* Enter your code here. Read input from STDIN. Print output to STDOUT */  
    long long n,m;
    scanf("%lld %lld",&n,&m);
    long long t;
    if(n<m)
        {
        t=m;m=n;n=t;
    }
    long long z;
    z=m-1+m*(n-1);
    printf("%lld",z);
    
    return 0;
}