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: Accepted)

#include <iostream>
#include <string>

namespace Mylib{
    using namespace std;
    
    void Instring(string& x){
        cin >> x;
    }
    
    void showString(string& x){
        cout << x << endl;
    }
    
    bool checkAtoB(string& x){
        for(int i=1;i<x.length();i++){
            if(x[i-1]!=x[i])return true;
        }
        return false;
    }
    void showflag(bool flg){
        if(flg==true){
            cout << "Yes" << endl;
            
        }else{
            cout << "No" << endl;
        }
    }
    
}
int main(void){
    std::string inStr;
    Mylib::Instring(inStr);
    bool flag;
    flag=Mylib::checkAtoB(inStr);
    Mylib::showflag(flag);
    
    
    
    
    return 0;
}