#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
using ll = long long;
#define rep(i,a,b) for(int i = a; i < b; ++i)
#define rrep(i,a,b) for(int i = a; i >= b; --i)
#define all(x) (x).begin(),(x).end()

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