#include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define all(v) begin(v), end(v)
using namespace std;
using P = pair<int,int>;
using ll = long long;
using vi = vector<int>;
using vll = vector<ll>;

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