//Normal

#define _GLIBCXX_DEBUG
#define ll long long
#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

void print(auto a){
  cout << a;
}

void prints(auto a){
  cout << a << " ";
}

void prints(){
  cout << " ";
}

void printl(auto a){
  cout << a << endl;
}

void printl(){
  cout << endl;
}

void fix(int n){
  cout << fixed << setprecision(n);
}

int main(){
  int A, B; cin >> A >> B;
  if(A < B) swap(A, B);
  
  int ans = -1;
  bool flag = true;
  
  while(true){
    if(flag){
      if(A != 0){
        ans++;
        A--;
        flag = !flag;
      }else{
        printl(ans);
        return 0;
      }
    }else{
      if(B != 0){
        ans++;
        B--;
        flag = !flag;
      }else{
        printl(ans);
        return 0;
      }
    }
  }
}