# include <bits/stdc++.h>

const int N=100010,INF=0x3f3f3f3f;

inline int read(void){
	int res,f=1;
	char c;
	while((c=getchar())<'0'||c>'9')
		if(c=='-') f=-1;
	res=c-48;
	while((c=getchar())>='0'&&c<='9')
		res=res*10+c-48;
	return res*f;
}

int dx[8]={-3,-3,-1,1,1,1,3,3};
int dy[8]={-1,1,-3,3,-3,3,-1,1};

int n;

bool l[N],c[N];

std::vector <std::pair <int,int> > d,ans,seq;

inline void ins(int x,int y){
	seq.push_back(std::make_pair(x,y));
	return;
}

void dfs(int x,int y,int dep){
	l[x]=c[y]=true,d.push_back(std::make_pair(x,y));
	
	if(dep==n){
		ans=d;//,printf("POSSIBLE! d = %llu",d.size());
		goto END;
	}
	
	for(int k=0;k<8;++k){
		int tx=x+dx[k],ty=y+dy[k];
		if(tx<1||tx>n||ty<1||ty>n||l[tx]||c[ty]) continue;
		dfs(tx,ty,dep+1);
	}
	
	END:
	l[x]=c[y]=false,d.pop_back();
	return;
}

inline void pr(void){
	puts("POSSIBLE");
	for(auto v:seq) printf("%d %d\n",v.first,v.second);
	
	exit(0);
	
	return;
}


inline void solve(int d){
	if(n-d>=12){
		ins(d+1,d+1),ins(d+4,d+2),ins(d+5,d+5),ins(d+2,d+6),ins(d+3,d+3),ins(d+6,d+4),ins(d+7,d+7);
		solve(d+6);
	}else{
		n=n-d;
		dfs(1,1,1);
		for(auto v:ans) if(v.first!=1||d==0) ins(d+v.first,d+v.second);
		pr();
	}
	return;
}

int main(void){
	n=read();
	
	if(n==1) ins(1,1),pr();
	else if(2<=n&&n<5) puts("IMPOSSIBLE"),exit(0);
	else if(n==5){
		ins(1,3),ins(4,2),ins(5,5),ins(2,4),ins(3,1);
		pr();
	}solve(0);



	return 0;
}