#include<bits/stdc++.h>
using namespace std; 
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep1(i, n) for (int i = 1; i < (int)(n); i++)
#define length size()
#define int long long
#define ll long long
int ctoi(const char c){
  switch(c){
    case '0': return 0;
    case '1': return 1;
    case '2': return 2;
    case '3': return 3;
    case '4': return 4;
    case '5': return 5;
    case '6': return 6;
    case '7': return 7;
    case '8': return 8;
    case '9': return 9;
    default : return -1;
  }
}
template<typename T> string join(vector<T> &vec ,const string &sp){
    int si = vec.length;
    if(si==0){
        return "";
    }else{
        stringstream ss;
        rep(i,si-1){
            ss << vec[i] << sp;
        }
        ss << vec[si - 1];
        return ss.str();
    }
}
const int mod = 1000000007;
long long modpow(long long a, long long n, long long mod) {
    long long res = 1;
    while (n > 0) {
        if (n & 1) res = res * a % mod;
        a = a * a % mod;
        n >>= 1;
    }
    return res;
}
signed main(void){
    string s;
    cin >> s;
    if(s[0] == s[1] && s[0] != s[2]) cout << "Yes" << endl;
    else cout << "No" << endl;
}