#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

int func(int m, int n)
    {
    if(m==1 && n==1)
        return 0;
    if(m>n)
        {
        return (1 + func(m/2,n) + func(m-m/2,n));
    }
    else
        {
        return (1 + func(m,n/2) + func(m,n-n/2));
    }
}


int main() {
    int m,n;
    cin>>m>>n;
    int row = m;
    int column = n;
    cout<<func(m,n);
    return 0;
}