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

int main() {
int a,b,n;
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */    
    scanf("%d %d",&a,&b);
    n=a*b-1;
    printf("%d",n);
    return 0;
}