#include <bits/stdc++.h>
using namespace std;
int main() {
  vector<string> v(5);
  int ok[10000];
  for (int i = 0; i < 4; i++) cin >> v[i];
  for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
      ok['#'] = ok['.'] = 0;
      for (int x = 0; x < 2; x++) {
        for (int y = 0; y < 2; y++) {
          ok[v[i + x][j + y]]++;
        }
      }
      if (ok['#'] < 2 || ok['.'] < 2) {
        cout << "YES" << endl;
        return 0;
      }
    }
  }
  cout << "NO\n";
  return 0;
}
