#include <bits/stdc++.h>
using namespace std;
using ll=long long;
using ld=long double;
ld pie=3.141592653589793;
ll inf=20000000000000;
ll mod=998244353;
int main(){
    string s;
    cin >> s;
    if (s[0]==s[1]&&s[1]!=s[2])
    {
        cout << "Yes" << endl;
    }else{
        cout << "No" << endl;
    }
    
}