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