Merkkijono

#include <iostream>
#include <string>

using namespace std;

int main()
{
	string str;
	cin >> str;

	for(unsigned int i = 0; i < str.length(); i++)
		if(!isalpha(str[i]))
		{
			str.erase(i, 1);
			i = 0;
		}

	for(unsigned int i = 0; i < str.length(); i++)
	{
		char current = str[i];

		unsigned int j = 0;
		for(j = 0; str[i + j] == current; j++);
		if(j > 1)
		{
			str.erase(i, j);
			i = 0;
		}
	}

	cout << str << endl;

}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: WRONG ANSWER

Test 3

Verdict: WRONG ANSWER

Test 4

Verdict: WRONG ANSWER

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED