```cpp

include[HTML_REMOVED]

include[HTML_REMOVED]

using namespace std;
int main(){
double n;
cin>>n;
if(n<=2000){
printf(“Isento”);
}
else if(n<=3000){
printf(“R$ %.2lf”,0.08*(n-2000));} else if(n<=4500){ printf(“R$ %.2lf”,0.081000+0.18(n-3000));}
else{
printf(“R$ %.2lf”,0.081000+0.181500+0.28*(n-4500));}
return 0;
}