#include <bits/stdc++.h>
using namespace std;
char c[4][4];
bool pd() {
  for (int i = 0; i < 3; ++i)
    for (int j = 0; j < 3; ++j) {
      int ans = 0;
      for (int k = 0; k < 2; ++k)
        for (int l = 0; l < 2; ++l) ans += (c[i + k][j + l] == c[i][j] ? 0 : 1);
      if (!ans) return true;
    }
  return false;
}
int main() {
  for (int i = 0; i < 4; ++i) scanf("%s", &c[i]);
  for (int i = 0; i < 4; ++i)
    for (int j = 0; j < 4; ++j) {
      c[i][j] = '.' - c[i][j] + '#';
      if (pd()) {
        puts("YES");
        return 0;
      }
      c[i][j] = '.' - c[i][j] + '#';
    }
  puts("NO");
  return 0;
}
