//#pragma GCC target("avx2")
//#pragma GCC optimize("O3")
//#pragma GCC optimize("unroll-loops")
#include <iostream>
#include <iomanip>
#include <algorithm>
#include <vector>
#include <string>
#include <set>
#include <map>
#include <cassert>
#include <cmath>
#include <tuple>
#include <queue>
#include <bitset>
#include <complex>
#define _USE_MATH_DEFINES
#include <math.h>
using namespace std;
using lg = long long;
using pii = pair<int, int>;
using pll = pair<lg, lg>;
#define TEST clog << "TEST" << endl
#define IINF 2147483647
#define LLINF 9223372036854775807LL
//#define AMARI 998244353
#define AMARI 1000000007
#define TEMOTO ((sizeof(long double) == 16) ? false : true)
#define TIME_LIMIT 1980 * (TEMOTO ? 1 : 1000)
#define el '\n'
#define El '\n'

#define MULTI_TEST_CASE false
void solve(void) {
    string s;
    cin >> s;
    if (s[0] == s[1] && s[1] != s[2]) {
        cout << "Yes" << el;
        return;
    }
    cout << "No" << el;
    return;
}

void calc(void) {
    return;
}

int main(void) {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int t = 1;
    if (MULTI_TEST_CASE)cin >> t;
    while (t--) {
        //calc();
        solve();
    }
    return 0;
}