#include <vector>
using namespace std;

int find_even_index (const vector <int> numbers) {


  int currentPos=0;
  for(int i=0;i<1000;i++){

  int check=0;
  int totalLeft,totalRight=0;

  for(int i=0;i<=currentPos;i++){
    totalLeft += numbers[i];
  }
  for(int i=numbers.size();i>currentPos;i--){
    totalRight += numbers[i];
  }

  if(totalLeft==totalRight){
    return currentPos+1;}
  if(currentPos=numbers.size()){
    return -1;}
  currentPos++;


}



}