#include <bits/stdc++.h>
#include <atcoder/all>
#define rep(i, n) for (int i=0; i<(n); i++)
#define len(x) (int)(x).size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
using namespace std;
using namespace atcoder;
using ll = long long;
using mint9 = atcoder::modint998244353;
using mint10 = atcoder::modint1000000007;

int main() {
   ios::sync_with_stdio(false);
   cin.tie(0);

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