#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  cin.sync_with_stdio(0);
  vector<string> v(4);
  cin >> v[0] >> v[1] >> v[2] >> v[3];
  for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
      int hashes = (v[i][j] == '#') + (v[i][j + 1] == '#') +
                   (v[i + 1][j] == '#') + (v[i + 1][j + 1] == '#');
      if (hashes != 2) {
        cout << "YES";
        return 0;
      }
    }
  }
  cout << "NO";
}
