#include <iostream>
#include <vector>
using namespace std;

int main() {
    int N, T;
    cin >> N >> T;

    vector<vector<int>> A(N, vector<int>(N));
    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            cin >> A[i][j];
        }
    }

    vector<pair<int, int>> path;

    for (int i = 0; i < N; i++) {
        if (i % 2 == 0) {
            // 左から右へ
            for (int j = 0; j < N; j++) {
                path.push_back(make_pair(i, j));
                if (path.size() == T) {
                    break;
                }
            }
        } else {
            // 右から左へ
            for (int j = N - 1; j >= 0; j--) {
                path.push_back(make_pair(i, j));
                if (path.size() == T) {
                    break;
                }
            }
        }

        if (path.size() == T) {
            break;
        }
    }

    cout << path.size() << endl;
    for (int k = 0; k < path.size(); k++) {
        cout << path[k].first << " " << path[k].second << endl;
    }

    return 0;
}