#include <iostream>
#include <unordered_map>
using namespace std;
char First(string s)
{
unordered_map<char,int> hash;
for(auto &c:s)
{
hash[c]++;
}
for(auto &c:s)
{
if(hash[c] == 1)
return c;
}
return ' ';
}
int main()
{
char s[] = "google";
char c = First(s);
cout<<c<<endl;
return 0;
}