include <bits/stdc++.h>

using namespace std;

bool zhishu(long long n) { for(long long i = 2;i<=n-1;i++){ if (n % i ==0){ return false; } } return true; } int main(){ long long n; cin >>n; if(n < 5 and n >= 0){ cout <<"empty"<<endl; return 0; } for(long long i = 2;i<=n-2;i++){ if(zhishu(i)and zhishu(i+2)){ cout <<i<<" "<<i+2<<endl; } } return 0; }