#include <bits/stdc++.h>
using namespace std;
int main() {
  char s[5][5];
  for (int i = 0; i < 4; i++) scanf("%s", s[i]);
  int flag = 0;
  for (int i = 0; i < 3; i++)
    for (int j = 0; j < 3; j++) {
      int sum = 0;
      if (s[i][j] == '#') sum++;
      if (s[i][j + 1] == '#') sum++;
      if (s[i + 1][j] == '#') sum++;
      if (s[i + 1][j + 1] == '#') sum++;
      if (sum != 2) {
        flag = 1;
        break;
      }
    }
  if (flag == 1)
    printf("YES\n");
  else
    printf("NO\n");
  return 0;
}
