#include<stdio.h>
struct book
{
    int q;
};
int main()
{
    int sum,last,dis;
    float final;
    struct vidyuth find;
    scanf("%d",&find.q);
    if (find.q<0)
{
    printf("Invalid input");
}    
else {
    sum = find.q * 100;
 if (find.q>=1&& find.q<=5)
 {
     dis=sum*0.15;
 }
 else if (find.q>10)
 {
     dis=sum*0.20;
 }
 final = sum.dis;
 printf("%.2f",final);
    
}
}