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

typedef modint998244353 mint;
typedef long long ll;

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