#include <iostream>
#include <fstream>

using namespace std;
int main()
{
freopen ("add.in", "r", stdin);
	freopen ("add.out", "w" , stdout);
int n,m,a;
cin>>n>>m;
for(int i=1;i<=n;i++)
{
    cin>>a;
}
    cout<<"impossible"<<endl;
    return 0;
}