#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using vi = vector<int>;
using vl = vector<long>;
using vll = vector<long long>;
using vs = vector<string>;
using vc = vector<char>;
using pll = pair<long long, long long>;
const int INF = 1e9;
using Graph = vector<vector<int>>;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

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