#include <bits/stdc++.h>

using i64 = long long;

constexpr int BufSize = 1 << 20;

inline char readChar() {
    static char buf[BufSize], *p1, *p2;
    static std::streambuf *inbuf = std::cin.rdbuf();
    return p1 == p2 && (p2 = (p1 = buf) + inbuf->sgetn(buf, BufSize), p1 == p2) ? EOF : *p1++;
}
template <typename T>
void read(T &x) {
    x = 0;
    char c = readChar();
    bool f = false;
    while (!std::isdigit(c)) {
        f |= c == '-';
        c = readChar();
    }
    while (std::isdigit(c)) {
        x = x * 10 + (c - '0');
        c = readChar();
    }
    if (f) {
        x *= -1;
    }
}

inline void printChar(char c) {
    static std::streambuf *outbuf = std::cout.rdbuf();
    outbuf->sputc(c);
}
template <typename T>
void print(T x) {
    if (x < 0) {
        printChar('-');
        x = -x;
    }
    static std::array<char, 50> stk;
    int top = 0;
    do {
        stk[top++] = x % 10 + '0';
        x /= 10;
    } while (x > 0);
    while (top--) {
        printChar(stk[top]);
    }
}

template <int n>
void solve(int x) {
    if (n < x) {
        solve<std::min(n + 1, 11)>(x);
        return;
    }
    const int m = 1 << n;

    static std::array<std::bitset<m>, m> a, b;
    for (int i = 0; i < m; ++i) {
        for (int j = 0; j < m; ++j) {
            int x;
            read(x);
            a[i][j] = x;
        }
    }

    for (int x = m / 4; x; x /= 2) {
        b = a;
        for (int i = 0; i < m; ++i) {
            a[i] ^= b[(i - x) & (m - 1)] ^ b[(i + x) & (m - 1)] ^
                    ((b[i] << x) | (b[i] >> (m - x))) ^ ((b[i] >> x) | (b[i] << (m - x)));
        }
    }

    int cnt = 0;
    for (int i = 0; i < m; ++i) {
        cnt += int(a[i].count());
    }

    print(cnt);
    printChar('\n');
    for (int i = 0; i < m; ++i) {
        for (int j = a[i]._Find_first(); j < m; j = a[i]._Find_next(j)) {
            print(i);
            printChar(' ');
            print(j);
            printChar('\n');
        }
    }
}

int main() {
    std::cin.tie(nullptr)->sync_with_stdio(false);

    int n;
    std::cin >> n;

    solve<1>(n);

    return 0;
}