Problem:
Score : 100 points

Problem Statement

In AtCoder City, there are three stations numbered 1, 2, and 3.

Each of these stations is operated by one of the two railway companies, A and B. A string S of length 3 represents which company operates each station. If S_i is A, Company A operates Station i; if S_i is B, Company B operates Station i.

To improve the transportation condition, for each pair of a station operated by Company A and one operated by Company B, there will be a bus service connecting them.

Determine if there is a pair of stations that will be connected by a bus service.

Constraints

Each character of S is A or B.

|S| = 3

Input

Input is given from Standard Input in the following format:

S

Output

If there is a pair of stations that will be connected by a bus service, print Yes; otherwise, print No.

Sample Input 1

ABA

Sample Output 1

Yes

Company A operates Station 1 and 3, while Company B operates Station 2.

There will be a bus service between Station 1 and 2, and between Station 2 and 3, so print Yes.

Sample Input 2

BBA

Sample Output 2

Yes

Company B operates Station 1 and 2, while Company A operates Station 3.

There will be a bus service between Station 1 and 3, and between Station 2 and 3, so print Yes.

Sample Input 3

BBB

Sample Output 3

No

Company B operates all the stations. Thus, there will be no bus service, so print No.

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

/*dismint|jjc*/
#include <bits/stdc++.h>
using namespace std;
#define forl(V, S, E) for(int V = S; V < E; V++)
#define ford(V, S, E) for(int V = S; V >= E; V--)
#define fore(E, X) for(auto &E:X)
#define println(X) cout << X << endl
#define printe(X) for(auto &E:X) cout << E << " "; cout << endl
typedef unordered_map<int, unordered_set<int>> graph;
typedef long long ll;

int main() {
	ios_base::sync_with_stdio(false); cin.tie(NULL);
	string s; cin >> s;
	if(count(s.begin(), s.end(), 'B') and count(s.begin(), s.end(), 'A')) println("YES");
	else println("NO");
}