#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
long int cut(long int m,long int n){
    if(m==1&&n==1)
        return 0;
    else{
        if(m>n)
        return cut(n,m/2) + cut(n,m-m/2) + 1;
        else
            return cut(m,n/2)+cut(m,n-n/2)+1;
    }
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */
    long int m,n;
    cin>>m>>n;
    long int c = cut(m,n);
    cout<<c;
    return 0;
}