string round(string &s)
{
	if(s.find_first_of(".") == string::npos)
		return s;

	int length = s.length();
	int remember = 0;

	for(int i = length - 1; i >= 0; --i)
	{
		if(s[i] == '.')
			continue;

		int x = s[i] - 48 + remember;
		
		if(x >= 5)
		{
			s[i] = '0';
			remember = 1;
		}
		else
		{
			s[i] = x + 48;
			remember = 0;
			break;
		}
	}
	if(remember == 1)
		s.insert(0, "1");

	return s;
}