//qoj8018
#include <bits/stdc++.h>
using namespace std;

const int N = (1 << 11) + 10;
int n, a[N][N], b[N][N];

void read(int &x){
	x = 0;
	char ch = getchar();
	int w = 1;
	while(ch < '0' || ch > '9'){
		if(ch == '-'){
			w = -w;
		}
		ch = getchar();
	}
	while(ch >= '0' && ch <= '9'){
		x = x * 10 + ch - '0';
		ch = getchar();
	}
	x *= w;
}

int main(){
	scanf("%d", &n);
	int m = n;
	n = (1 << n);
	for(int i = 0; i < n; ++ i){
		for(int j = 0; j < n; ++ j){
			scanf("%d", &a[i][j]);
		}
	}
	for(int k = m - 2; k >= 0; -- k){
		int x = (1 << k), y = n;
		for(int i = 0; i < n; ++ i){
			for(int j = 0; j < n; ++ j){
				if(a[i][j] == 1){
					b[i][j] ^= 1;
					b[(i+x)%y][j] ^= 1;
					b[i][(j+x)%y] ^= 1;
					b[(i-x+y)%y][j] ^= 1;
					b[i][(j-x+y)%y] ^= 1;
				}
			}
		}
		for(int i = 0; i < n; ++ i){
			for(int j = 0; j < n; ++ j){
				a[i][j] = b[i][j];
				b[i][j] = 0;
			}
		}
	}
	int cnt = 0;
	for(int i = 0; i < n; ++ i){
		for(int j = 0; j < n; ++ j){
			if(a[i][j]){
				++ cnt;
			}
		}
	}
	printf("%d\n", cnt);
	for(int i = 0; i < n; ++ i){
		for(int j = 0; j < n; ++ j){
			if(a[i][j]){
				printf("%d %d\n", i, j);
			}
		}
	}
	return 0;
}