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)

#include<bits/stdc++.h>
using namespace  std;

typedef  long long int ll;
typedef  vector<int> vi;
#define  IOS ios::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
#define  pb push_back
#define  fn for(int i=0;i<n;i++)
#define  all(x) x.begin(), x.end()
#define  endl "\n"


void solve()
{
	// write your code here :
string s;
	cin>>s;
	if(s[0]==s[1] and s[1]==s[2])
		cout<<"NO";
	else cout<<"YES";
	cout<<endl;
}

int main()
{
	IOS
    // #ifndef ONLINE_JUDGE
    // freopen("input.txt","r",stdin);
    // freopen("output.txt","w",stdout);
    // #endif
	// int t;
	// cin>>t;
	// while(t--)
	solve();
}