function split remove string

string strchuoi = "helo ai do a o do vay" ; ex:
int n =Convert.ToInt32(strchuoi.Length.ToString());
string[] mang= strchuoi.Split(' ');
int sodoan=0; count
foreach(string y in mang)
{
sodoan=sodoan+1;
}

Response.Write(mang[sodoan-1]);
using trim cut space in string