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

int main() {

    long long n, m;
    scanf("%lld %lld", &n, &m);
    
    long long ans1 = (n - 1) + n * (m - 1);
    long long ans2 = (m - 1) + m * (n - 1);
            
    long long ans = (ans1 >= ans2 ? ans2 : ans1);
    
    if(m == 1) ans = n-1;
    if(n == 1) ans = m-1;
        
    printf("%lld", ans);   
    return 0;
}