/*
#include<vector>
#include<iostream>
#include<math.h>
#include<algorithm>*/
//#include<unordered_map>
#include<string>
#include<set>
#include<vector>
#include<cctype>
//#include<algorithm>
//#include<queue>
#include<iostream>
#include<cstdio>
#include<math.h>
#include<stdlib.h>
#include<utility>
using namespace std;

vector<bool> flag(10001,false);
int main()
{

  //  vector< pair<int,int>> ans;
    vector<int> res;
    int n;
    cin>>n;
    for(int i = 2; i <= n ;i++)
    {
        if(flag[i]) continue;
        res.push_back(i);
        for(int j = i+i;j<=n;j=j+i)
        {
            flag[j]= true;
        }
    }
    int countn = 0;
    for(int i = 0;i<res.size();i++)
    {
        if(res[i]-res[i-1]==2)
        {
            cout<<res[i-1]<<" "<<res[i]<<endl;
            countn++;
        }
    }
    if(!countn) cout<<"empty";
    return 0;
}