#include<bits/stdc++.h>using namespace std;int a,b,ans;int main(){ cin>>a>>b; if(a==b) { ans=a*4-b*2; } if(a>b) { ans=a+a+a+b+b+b; ans=ans/3; } if(a<b) { ans=a+b+b+a; ans=ans/2; } cout<<ans;}