#include <bits/stdc++.h>
using namespace std;

void fast_io() {
	ios_base::sync_with_stdio(false);
	cin.tie(nullptr);
}

int main() {
	fast_io();
	string s;
	cin >> s;
	if (s[0] == s[1] && s[1] != s[2]) {
		cout << "Yes" << endl;
	} else {
		cout << "No" << endl;
	}
}