#include <cstdlib>
#include <fstream>
#include <cassert>

using namespace std;

#define MAX_N 1001
#define MAX_H 1001
#define UNDEF -1

int main() {

  ofstream fout("output.txt"); 
  assert(fout);
  fout << -1;
  fout.close();
  return 0;
}