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