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