#include <iostream>
#include <vector>
using namespace std;

bool buscarDato(const vector<int> & v, int dato, int fin) {

  return fin >= 0 && (v[fin] == dato || buscarDato(v, dato, fin - 1));

}

bool buscarDato(const vector<int> & v, int dato) {

  return buscarDato(v, dato, v.size() - 1);

}


int main () {

  vector<int> v = {33, 27, 10, 15};

  for (int i = 0; i < v.size(); i++)
    if (buscarDato(v, v[i]))
      cout << i << " OK" << endl;
    else
      cout << i << " ERROR" << endl;

  if (! buscarDato(v, 99))
    cout << "OK" << endl;
  else
    cout << "ERROR" << endl;

}