#include<bits/stdc++.h> using namespace std; bool h(int n) { for(int i = 3; i * i <= n; i++) if(n % i == 0) return false; return true; } int main() { int n; cin >> n; bool f = false; for (int i = 3 ; i + 2 <= n ; i += 2 ) { if(h(i) && h(i+2)) cout<< i <<' '<< i+2 << endl , f = true; } if(!(f)) cout<<"empty"; }