public static boolean chkBox(char[][] arr,int x,int y){
		boolean res = true;
		Set<Character> set = new HashSet<>();
		for(int i=x;i<x+3;i++){

			for(int j=y;j<y+3;j++){
				if(arr[i][j]!='.')
				if(set.contains(arr[i][j])){
					res = false;
					break;
				}else{
					set.add(arr[i][j]);
				}
			}
			if(!res)
				break;
		}
		return res;
	}