#include <iostream>
#include <vector>
#include <cmath>
#include <map>
#include <set>
#include <iomanip>
#include <queue>
#include <algorithm>
#include <numeric>
#include <deque>
#include <complex>
#include <cassert>

using namespace std;
using ll = long long;

int main(){

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

    return 0;
}