#include<bits/stdc++.h>
#define chmin(x,y) (x) = min((x),(y))
#define chmax(x,y) (x) = max((x),(y))
using namespace std;
using ll = long long;
const ll mod = 998244353;
const vector<int> dx = {1,0,-1,0}, dy = {0,1,0,-1};
using Graph = vector<vector<int>>;

int main(){
  // input
  string s; cin >> s;
  // solve
  cout << (s[0] == s[1] && s[1] != s[2]? "Yes":"No") << endl;
  // output
  
}