#include<cstdio>
#include<vector>
#include<queue>
#include<cstring>
#include<iostream>
#include<algorithm>
#include<ctime>
#include<bitset>
#include<random>
#include<assert.h>
#define pb emplace_back
#define mp make_pair
#define fi first
#define se second
#define dbg(x) cerr<<"In Line "<< __LINE__<<" the "<<#x<<" = "<<x<<'\n'
#define dpi(x,y) cerr<<"In Line "<<__LINE__<<" the "<<#x<<" = "<<x<<" ; "<<"the "<<#y<<" = "<<y<<'\n'
#define DE(fmt,...) fprintf(stderr, "Line %d : " fmt "\n",__LINE__,##__VA_ARGS__)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int>pii;
typedef pair<ll,int>pli;
typedef pair<ll,ll>pll;
typedef pair<int,ll>pil;
typedef vector<int>vi;
typedef vector<ll>vll;
typedef vector<pii>vpii;
typedef vector<pll>vpll;
template<typename T>T cmax(T &x, T y){return x=x>y?x:y;}
template<typename T>T cmin(T &x, T y){return x=x<y?x:y;}
template<typename T>
T &read(T &r){
	r=0;bool w=0;char ch=getchar();
	while(ch<'0'||ch>'9')w=ch=='-'?1:0,ch=getchar();
	while(ch>='0'&&ch<='9')r=r*10+(ch^48),ch=getchar();
	return r=w?-r:r;
}
template<typename T1,typename... T2>
void read(T1 &x,T2& ...y){read(x);read(y...);}
const int N=2050;
int n;
bitset<N>a[N],b[N];
int bit(int x){return 1<<x;}
signed main(){
//	#ifdef do_while_true
//		assert(freopen("set.in","r",stdin));
//		assert(freopen("set.out","w",stdout));
//	#endif
	read(n);
	int w=bit(n);
	for(int i=0;i<w;i++)
		for(int j=0;j<w;j++){
			int x;read(x);
			if(x)a[i].set(j);
		}
	for(int k=n-1;k>=0;k--){
		for(int i=0;i<w;i++)
			for(int j=0;j<w;j++)
				if(a[i][j]){
					b[i][j].flip();
					b[(i-bit(k)+w)%w][j].flip();
					b[(i+bit(k))%w][j].flip();
					b[i][(j-bit(k)+w)%w].flip();
					b[i][(j+bit(k))%w].flip();
				}
		for(int i=0;i<w;i++){
			a[i]=b[i];
			b[i].reset();
		}
	}
	int tot=0;
	for(int i=0;i<w;i++)tot+=a[i].count();
	cout<<tot<<'\n';
	for(int i=0;i<w;i++)
		for(int j=0;j<w;j++)
			if(a[i][j])
				cout<<i<<' '<<j<<'\n';
    #ifdef do_while_true
//		cerr<<'\n'<<"Time:"<<1.0*clock()/CLOCKS_PER_SEC*1000<<" ms"<<'\n';
	#endif
	return 0;
}