// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
int main() {
    // Input
    string S;
    cin >> S;

    // Output
    cout << (S[0] == S[1] && S[1] != S[2] ? "Yes" : "No") << endl;
}