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