#include <bits/stdc++.h>
int num[4][4];
int main() {
  int i, j, sum;
  for (i = 0; i < 4; i++) {
    for (j = 0; j < 4; j++) {
      num[i][j] = (getchar() == '.' ? 0 : 1);
    }
    getchar();
  }
  for (i = 0; i < 3; i++) {
    for (j = 0; j < 3; j++) {
      sum = 0;
      sum = num[i][j] + num[i][j + 1] + num[i + 1][j] + num[i + 1][j + 1];
      if (sum != 2) break;
    }
    if (sum != 2) break;
  }
  if (sum != 2)
    printf("YES\n");
  else
    printf("NO\n");
  return 0;
}
