Am nevoie de acest exercitiu,rapid.Va multumesc.(sper sa imi intelegeti scrisul)

include <iostream>
using namespace std;
long long s,s1;
int main()
{
cin>>s;
if (s>=20) s1=s-s*20/100;
else s1=s-s*10/100;
cout<<s1;
return 0
}