```go
package main

import (
	"fmt"
)

func main() {
	grid := make([]string, 4)
	for i := 0; i < 4; i++ {
		fmt.Scan(&grid[i])
	}

	for i := 0; i < 3; i++ {
		for j := 0; j < 3; j++ {
			black := 0
			white := 0
			for di := 0; di < 2; di++ {
				for dj := 0; dj < 2; dj++ {
					if grid[i+di][j+dj] == '#' {
						black++
					} else {
						white++
					}
				}
			}
			if black >= 3 || white >= 3 {
				fmt.Println("YES")
				return
			}
		}
	}
	fmt.Println("NO")
}
```