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 Java8 (OpenJDK 1.8.0) (judge verdict: Runtime Error)

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws IOException{
		InputStreamReader in = new InputStreamReader(System.in);
		BufferedReader br = new BufferedReader(in);
		StringBuilder preSb = new StringBuilder();
		StringBuilder sb = new StringBuilder(br.readLine());
		int q = Integer.parseInt(br.readLine());
		
		boolean reverseFlg = false;
		String line = null;
		for(int i=0;i<q;i++) {
			line = br.readLine();
			char[] arr = line.toCharArray();
			if(arr[0]=='1') {
				reverseFlg = !reverseFlg;
			}else {
				if((arr[2]=='1' && !reverseFlg) || (arr[2]=='2' && reverseFlg)) {
//					sb.insert(0, arr[4]);
					preSb.append(arr[4]);
				} 
				else {
					sb.append(arr[4]);
				}
				
			}
		}
		br.close();
		preSb.reverse();
		sb.append(preSb);
		if(reverseFlg) {
			sb.reverse();
		}
		System.out.println(sb.toString());
		
	}
	
	

}