#include <bits/stdc++.h>
using namespace std;
int main() {
  char input[4][4];
  for (int row = 0; row < 4; row += 1) {
    for (int col = 0; col < 4; col += 1) {
      cin >> input[row][col];
    }
  }
  bool resault = 0;
  for (int i = 0; i < 3; i += 1) {
    if (resault) {
      break;
    }
    for (int j = 0; j < 3; j += 1) {
      if (resault) {
        break;
      }
      int white = 0, dark = 0;
      for (int row = i; row <= i + 1; row += 1) {
        for (int col = j; col <= j + 1; col += 1) {
          if (input[row][col] == '#' ? dark += 1 : white += 1)
            ;
        }
        if (dark >= 3 || white >= 3) {
          resault = 1;
          break;
        }
      }
    }
  }
  if (resault ? cout << "YES" : cout << "NO")
    ;
  return 0;
}
