#include <bits/stdc++.h>
using namespace std;
int main() {
  char a[5][5];
  for (int i = 0; i < 4; i++) {
    scanf("%s", a[i]);
  }
  bool f = false;
  for (int i = 0; i < 3; i++) {
    for (int j = 0; j < 3; j++) {
      int w = 0, b = 0;
      if (a[i][j] == '.')
        b++;
      else
        w++;
      if (a[i + 1][j] == '.')
        b++;
      else
        w++;
      if (a[i][j + 1] == '.')
        b++;
      else
        w++;
      if (a[i + 1][j + 1] == '.')
        b++;
      else
        w++;
      if (b >= 3 || w >= 3) {
        f = true;
        break;
      }
    }
  }
  if (f)
    printf("YES\n");
  else
    printf("NO\n");
  return 0;
}
