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

void solve();

signed main(){
	cin.tie(nullptr)->sync_with_stdio(false);
	cout<<fixed<<setprecision(15);

	int T=1;

	//cin>>T;
	
	while(T--)solve();

	return 0;
}

void solve(){
	string S;cin>>S;
	cout<<(S[0]==S[1]&&S[0]!=S[2]?"Yes":"No")<<endl;
}