static void Main(string[] args)
string input = Console.ReadLine();
permute(input, 0, input.Length - 1);
static string swap(string s, int pos1, int pos2)
char[] charArray = s.ToCharArray();
charArray[pos1] = charArray[pos2];
string newString = new string(charArray);
static void permute(string str, int l, int r)
for (int i = l; i <= r; i++)