#include <bits/stdc++.h>
using namespace std;
char s[4][4];
bool f(int m, int n) {
  int i, j;
  int w = 0, b = 0;
  for (i = m; i <= m + 1; ++i)
    for (j = n; j <= n + 1; ++j) {
      if (s[i][j] == '#')
        ++b;
      else
        ++w;
    }
  if (b >= 3 || w >= 3) return 1;
  return 0;
}
int main() {
  for (int i = 0; i < 4; ++i) gets(s[i]);
  for (int i = 0; i < 3; ++i)
    for (int j = 0; j < 3; ++j) {
      if (f(i, j)) {
        cout << "YES" << endl;
        return 0;
      }
    }
  cout << "NO" << endl;
  return 0;
}
