`
include[HTML_REMOVED]
include[HTML_REMOVED]
using namespace std;
string str;
int tong[1000001];
int main(){
cin>>str;
for(int i=0;i<str.size();i){
tong[str[i]-‘a’];
}
for(int i=0;i<str.size();i++){
if(tong[str[i]-‘a’]==1){cout<<str[i];return 0;}
}
cout<<”no”;
}
`