#include<bits/stdc++.h>
int main()
{
double a,b;
scanf("%lf", &a);
if(a>=0 && a<=2000)
printf("Isento\n");
else if(a>=2000.01 && a<=3000)
{
a-=2000;
b= a*.08;
printf("R$ %.2lf\n",b);
}
else if(a>=3000.01 && a<=4500)
{
a-=3000;
b= a*.18+80;
printf("R$ %.2lf\n",b);
}
else
{
a-=4500;
b= a*.28+350;
printf("R$ %.2lf\n",b);
}
return 0;
}
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