import static java.lang.System.err;

public class Main {
	public static void main(String[] args) {
		java.io.PrintWriter out = new java.io.PrintWriter(System.out);
		new Main(out);
		out.flush();
		err.flush();
	}

	public Main(java.io.PrintWriter out) {
		try (java.util.Scanner sc = new java.util.Scanner(System.in)) {
			char[] S = sc.next().toCharArray();
			out.println(S[0] == S[1] && S[1] != S[2] ? "Yes" : "No");
		}
	}
}