/**
 * @author : cyb1010
 * @date   : 2024-01-19 08:22:06
 * @file   : set.cpp
 */
#include <bits/stdc++.h>
using namespace std;
#define fo(s) freopen(s ".in", "r", stdin), freopen(s ".out", "w", stdout)
#define fi first
#define se second
typedef double db;
typedef long double ldb;
typedef long long ll;
typedef unsigned long long ull;
typedef bitset<2048> BS;
int __, n, l, cnt;
BS a[2048], b[2048], ans[2048];
int main() {
    // fo("set");
    cin.tie(0)->sync_with_stdio(0);
    cin >> n, l = 1 << n;
    for (int i = 0, x; i < l; i++)
        for (int j = 0; j < l; j++) cin >> x, a[i][j] = x;
    while (n--) {
        for (int i = 0; i < l; i++)
            for (int j = 0; j < l; j++)
                if (a[i][j])
                    b[i].flip(j), b[i].flip((j + (1 << n)) & (l - 1)),
                        b[i].flip((j + l - (1 << n)) & (l - 1)),
                        b[(i + (1 << n)) & (l - 1)].flip(j),
                        b[(i + l - (1 << n)) & (l - 1)].flip(j);
        for (int i = 0; i < l; i++) a[i] = b[i], b[i].reset();
    }
    for (int i = 0; i < l; i++) cnt += a[i].count();
    cout << cnt << endl;
    for (int i = 0; i < l; i++)
        for (auto j = a[i]._Find_first(); j < l; j = a[i]._Find_next(j))
            cout << i << " " << j << "\n";
    return 0 ^ __ ^ 0;
}