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

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