Merkkijono

import java.util.Scanner;
 
public class Merkkijono {
 
	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
 
		String mjono = s.nextLine();
		int pituus = mjono.length();
		int j = 0;
		int k = 0;
		try {
			for (int i = 0; i < pituus; i++) {
				char c = mjono.charAt(i);
				k = i;
					if (c == mjono.charAt(i + 1)) {
						for (int i2 = i; mjono.charAt(i2) == mjono.charAt(i); i2++) {
							j++;
						}
						mjono = mjono.substring(0, i) + mjono.substring(i + j);
						i = -1;
						j = 0;
					}
				}
		} catch (Exception e) {
			mjono = mjono.substring(0, k) + mjono.substring(k + j);
		}
		
		System.out.println(mjono);
		}
		
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED