#include <bits/stdc++.h>
using namespace std;
int main() {
  char M[4][5];
  for (int i = 0; i < 4; ++i) scanf("%s", M[i]);
  for (int i = 0; i < 3; ++i) {
    for (int j = 0; j < 3; ++j) {
      int cont = (M[i][j] == '#' ? 1 : 0) + (M[i + 1][j] == '#' ? 1 : 0) +
                 (M[i][j + 1] == '#' ? 1 : 0) +
                 (M[i + 1][j + 1] == '#' ? 1 : 0);
      if (cont != 2) {
        puts("YES");
        return 0;
      }
    }
  }
  puts("NO");
  return 0;
}
