string IntToString(int n)
{
	// This function converts from int to string.
	// Note: There is a similar function in C++.
	string s = "", t = "";
	char c;
	int i, m, len, p = n;
	n = abs(n);
	if (n == 0)
	{
		t = t + char(48);
		return t;
	}
	while (n != 0)
	{
		m = n % 10;
		c = char(m + 48);
		s = s + c;
		n = n / 10;
	}
	len = s.length();
	for (i = len - 1; i >=0; i--)
		t = t + s[i];
	if (p < 0)
		t = "-" + t; 
	return t;
}