#include<stdio.h>
int main()
{
 float a,l;
 scanf("%f",&a);
 if(a>=100)
 {l=3.95+(a-100)/100;
 printf("%f\n",l);}
 else if(100>a>=60)
 {l=3.35+(a-60)*0.015;
 printf("%f\n",l);}
else if(60>a>=40)
 {l=2.75+(a-40)*0.03;
 printf("%f\n",l);}
else if(40>a>=20)
 {l=1.75+(a-20)*0.05;
 printf("%f\n",l);}
else if(20>a>=10)
 {l=1+(a-10)*0.075;
 printf("%f\n",l);}
else if(10>a>=0)
 {l=a*0.1;
 printf("%f\n",l);}
 return 0;
}