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

int main(){
  vector<int> v;
  for(int i=0; i<10; i++){
    v.push_back(i*i);
  }
  cout << v[4] << " " << v.size() << endl;
  v[3]=-1;
  cout << v[3] << endl;
}

/*
[jaagup@minitorn cpp]$ ./a.out
16 10
-1
*/