#include<stdio.h>
int main()
{
    double a = 0.0f;
    scanf("%lf",&a);
    double sum;
    if(a>=100&&a<500)
    {
        sum = a*0.9;
        printf("%.1lf",sum);
    }
    else if(a>=500&&a<2000)
    {
         sum = a*0.8;
        printf("%.1lf",sum);
    }
    else if(a>=2000&&a<5000)
    {
         sum = a*0.7;
        printf("%.1lf",sum);
    }
    else if(a>=5000)
    {
         sum = a*0.6;
        printf("%.1lf",sum);
    }
    else {
        printf("%.1lf",a);
    }
    return 0;
}