using System;

public class Test
{
	public static void Main()
	{
		string s="Something1, something2, something3, something4,something5";
		Console.WriteLine(getSpecifiedIndexOf(s,',',2));
	}
	public static int getSpecifiedIndexOf(string str,char ch,int index){
		int i = 0,o=1;
		while ((i = str.IndexOf(ch, i)) != -1)
		{
			if(o==index)return i;
		    o++;
		    i++;
		}
		return 0;
	}
}