using System;
class Program
{
static string getNonRepeatedCharacters(string s) {
int[] count = new int[256];
int i;
for (i = 0; i < s.Length; i++)
if (s[i] != ' ')
count[(int)s[i]]++;
int len = i;
string nrc = "";
for (i = 0; i < len; i++)
if (count[(int)s[i]] == 1)
nrc += s[i];
return nrc;
}
static void Main()
{
string s = "c sharp php c++";
string nrc = getNonRepeatedCharacters(s);
Console.WriteLine(nrc);
}
}
/*
run:
sar
*/