#include<bits/stdc++.h>
using namespace std;
inline int read(){
    int x=0;char ch=getchar();
    while(ch<'0'||ch>'9')ch=getchar();
    while(ch>='0'&&ch<='9')x=(x<<1)+(x<<3)+(ch^48),ch=getchar();
    return x;
}
int stk[20],top;
inline void write(int x){
    if(x==0){putchar('0');return;}
    while(x)stk[++top]=x%10,x/=10;
    while(top)putchar(stk[top]+'0'),--top;
}
const int N=2222;
int n,m,a[N][N],b[N][N];
vector<pair<int,int> > ans;
int main(){
    n=read();m=(1<<n);
    for(int i=0;i<m;i++)
        for(int j=0;j<m;j++)a[i][j]=read();
    for(int d=(1<<n-2);d;d>>=1){
        for(int i=0;i<m;++i)
            for(int j=0;j<m;++j)if(a[i][j]){
                b[i][j]^=1;b[(i+d)%m][j]^=1;b[i][(j+d)%m]^=1;
                b[(i+m-d)%m][j]^=1;b[i][(j+m-d)%m]^=1;
            }
        for(int i=0;i<m;++i)
            for(int j=0;j<m;++j)
                a[i][j]=b[i][j],b[i][j]=0;
    }
    for(int i=0;i<m;++i)
        for(int j=0;j<m;++j)
            if(a[i][j])ans.push_back({i,j});
    write(ans.size());putchar('\n');
    for(auto x:ans)write(x.first),putchar(' '),
                   write(x.second),putchar('\n');
    return 0;
}
//g++ set.cpp -o set.exe -static -std=c++14 -O2