#include <iostream>
#include <cstdio>

using namespace std;

int main()
{
    double a;
    cin>>a;
    if (a<=2000.00) printf("Isento");
    else if(a<=3000.00) printf("R$ %.2lf",(a-2000.00)*0.08);
    else if(a<=4500.00) printf("R$ %.2lf",80+(a-3000.00)*0.18);
    else if(a>4500.00) printf ("R$ %.2lf",80+270+(a-4500.00)*0.28);
    return 0;
}