#include<bits/stdc++.h>
using namespace std;
const int N=1<<11;
int n,m,a[N][N],b[N][N],cnt;
inline int md(int x){
	if(x<0)return x+m;
	if(x>m)return x-m;
	return x;
}
int main(){
	scanf("%d",&n);
	m=1<<n;
	for(int i=0;i<m;++i)for(int j=0;j<m;++j)scanf("%d",&a[i][j]);
	for(int k=m>>2;k;k>>=1){
		memset(b,0,sizeof(0));
		for(int i=0;i<m;++i)for(int j=0;j<m;++j)if(a[i][j]){
			b[i][j]^=1;
			b[md(i-k)][j]^=1;
			b[md(i+k)][j]^=1;
			b[i][md(j+k)]^=1;
			b[i][md(j-k)]^=1;
		}
		memcpy(a,b,sizeof(b));
	}
	for(int i=0;i<m;++i)for(int j=0;j<m;++j)cnt+=a[i][j];
	printf("%d\n",cnt);
	for(int i=0;i<m;++i)for(int j=0;j<m;++j)if(a[i][j])printf("%d %d\n",i,j);
	return 0;
}