#include<iostream.h>
#include<fstream.h>
int main()
{
 long a,i,
 b,x;
 ifstream f("loto.in");
 ofstream g("loto.out");
  f>>a;
  f>>b;
  for(i=1;i<=a;i++)
	f>>x;
  g<<"-1";
  f.close();
  f.close();
  return 0;
}