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