#include <bits/stdc++.h>
using namespace std;

int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);

  int N, K;
  cin >> N >> K;

  vector<string> d(N);
  for (int i = 0; i < N; ++i) cin >> d[i];

  vector<vector<bool>> cut(N, vector<bool>(N, false));
  vector<pair<int, int>> ans;

  mt19937 rng(123456789);

  while ((int)ans.size() < K) {
    int bestD = -1;

    for (int i = 0; i < N; ++i) {
      for (int j = 0; j < N; ++j) {
        if (cut[i][j]) continue;
        int v = d[i][j] - '0';
        if (v >= 7) bestD = max(bestD, v);
      }
    }

    if (bestD < 7) break;

    vector<pair<int, int>> candidates;

    for (int i = 0; i < N; ++i) {
      for (int j = 0; j < N; ++j) {
        if (!cut[i][j] && d[i][j] - '0' == bestD) {
          candidates.emplace_back(i, j);
        }
      }
    }

    auto [r, c] = candidates[rng() % candidates.size()];

    cut[r][c] = true;
    ans.emplace_back(r, c);

    int dist = 1;
    bool leftAlive = true;
    bool rightAlive = true;

    while ((leftAlive || rightAlive) && (int)ans.size() < K) {
      if (leftAlive) {
        int nc = c - dist;

        if (nc < 0 || d[r][nc] - '0' < 7) {
          leftAlive = false;
        } else {
          if (!cut[r][nc]) {
            cut[r][nc] = true;
            ans.emplace_back(r, nc);

            if ((int)ans.size() == K) break;
          }
        }
      }

      if (rightAlive) {
        int nc = c + dist;

        if (nc >= N || d[r][nc] - '0' < 7) {
          rightAlive = false;
        } else {
          if (!cut[r][nc]) {
            cut[r][nc] = true;
            ans.emplace_back(r, nc);

            if ((int)ans.size() == K) break;
          }
        }
      }

      ++dist;
    }
  }

  cout << ans.size() << '\n';
  for (auto [i, j] : ans) {
    cout << i << ' ' << j << '\n';
  }

  return 0;
}