#include<iostream>
#include<string>
#include <cstring>
#include <vector>
#include<algorithm>
using namespace  std;
typedef  long long LL;
typedef  pair<int,int> PII;
const LL N=1e6+10,mod=998244353;
int n;
int m;
string s;
int a[1000010];
LL cnt1[200],cnt2[200];
bool col[N],row[N];
int num,vis;
vector<PII>ans;
int dx[]={1,3,3,1,-1,-3,-3,-1},dy[]={3,1,-1,-3,-3,-1,1,3};
void dfs(int x,int y){
    if(vis)return;
    if(x<1||x>n||y<1||y>n)return;
    if(col[x]||row[y])return;
    num++;
    col[x]=row[y]=1;
    ans.push_back({x,y});
    if(num==n){
       for(auto k:ans)
           cout<<k.first<<' '<<k.second<<endl;
       vis=1;
        return ;
    }
    for(int i=0;i<8;i++)
        dfs(x+dx[i],y+dy[i]);
        col[x]=row[y]=0;
        num--;
        ans.pop_back();
}
int main()
{   //LL ans=0;
    cin>>n;
    if(n==1){
        puts("POSSIBLE");
        cout<<1<<' '<<1<<endl;
        return  0;
    }else if(n<5){puts("IMPOSSIBLE");return 0;}

    puts("POSSIBLE");

    int pos=0;
    while(pos+18<n){
        cout<<pos+1<<' '<<pos+3<<endl;
        cout<<pos+4<<' '<<pos+2<<endl;
        cout<<pos+7<<' '<<pos+1<<endl;
        cout<<pos+6<<' '<<pos+4<<endl;
        cout<<pos+3<<' '<<pos+5<<endl;
        cout<<pos+2<<' '<<pos+8<<endl;
        cout<<pos+5<<' '<<pos+7<<endl;
        cout<<pos+8<<' '<<pos+6<<endl;
        cout<<pos+9<<' '<<pos+9<<endl;

        for(int i=1;i<=9;i++)col[pos+i]=row[pos+i]=1,num++;
        pos+=9;
    }
    dfs(pos+1,pos+3);
    return 0;
}