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