#define _USE_MATH_DEFINES
#include  <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
#include <string>
#include<math.h>
#include<iomanip>
#include<stdio.h>
#include <stdlib.h>
#include<stdio.h>
#include <queue>
#include<map>
#include <sstream>
#include<set>
#include<stack>
#include<time.h>
#include <sys/types.h>
#include <tuple>


typedef long long int ll;
//#include<bits/stdc++.h>


using namespace std;



int main()
{

    int Q;
    Q = 1;
//    cin >> Q;
    
    
    while (Q--) {

        int a, b;
        cin >> a>>b;
        if (a > b)swap(a, b);
        b--;
        int ans = 0;
        while (1) {
            
            if (ans % 2==0)a--;
            else b--;
            if (a < 0 || b < 0)break;
            ans++;
        }
        
        cout << ans << endl;
        
        


    }
    return 0; 
}