Task 1

Task1.cs

// Created in Linqpad
void Main()
{
	// 'baaaa' = -1
	// 'dog' = 8
	// 'aabab' = 3 -> 'aa' + 'ba' + 'b'
	// 'aabaa' = 0 -> 'aa' + 'baa'
	// 'adoag' = 6 -> 'a' + 'd' + 'oa' + 'g' 
	calculate("baaaa").Dump();
	calculate("dog").Dump();
	calculate("aabab").Dump();
	calculate("aabaa").Dump();
	calculate("adoag").Dump();
}

public int calculate(string word)
{
	if (word.Contains("aaa")) return -1;
	if (!word.Contains("a")) return getCount(word);
	return getCount(word.Replace("a", "")) - word.Count(c => c == 'a');
}

public int getCount(string word)
{
	return (word.Count() + 1) * 2;
}