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

int main() {
    long int a,b,c;
    scanf("%ld",&a);
    scanf("%ld",&b);
    c=((a*b)-1);
    printf("%ld",c);

    /* Enter your code here. Read input from STDIN. Print output to STDOUT */    
    return 0;
}