1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
#include<bits/stdc++.h>
using namespace std;

int main(){
ios_base::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);

int k; cin>>k;

if(k<100){
    cout<<"100\n";
    for(int i=1; i<100; i++){
        cout<<i+1;
        if(i<k)cout<<" 100\n";
        else cout<<" -1\n";
    }
    cout<<"-1 -1";
}


return 0;
}