Merkkijono

//#include "stdafx.h"
#include <iostream>
#include <string>

using namespace std;

int main()
{
	string text;
	cin >> text;
	while (true)
	{
		int len = text.length();
		int count = 1;
		char ch = text[0];
		for (int i = 1; i < len; i++)
		{
			if (ch == text[i])
			{
				count++;
			}
			else if (count > 1)
			{
				text.erase(i - count, count);
				break;
			}
			else
			{
				count = 1;
				ch = text[i];
				continue;
			}

			if (i + 1 == len)
			{
				text.erase(i - count + 1, count);
			}
		}

		if (count < 2)
		{
			break;
		}
	}
	cout << text << '\n';
    return 0;
}

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