答案？

#include <iostream>
using namespace std;
int main(){
int a;
cin>>a;
if(a<=2){
cout<<6;
}
else if(a>=2&&a<=10){
cout<<6+1.8*(a-2);
}else{
cout<<6+1.8*8+1.8*(1+0.5)*(a-10);
}

}