#pragma GCC target("avx2")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#include<bits/stdc++.h>
using namespace std;
using ll = long long int;
using ull = unsigned long long int;
using ld = long double;
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    string S;
    cin >> S;
    if(S[0] == S[1] && S[0] != S[2]) cout << "Yes" << endl;
    else cout << "No" << endl;
}