#include <stdio.h>

int main()
{
    int a;
    float b;
    scanf("%d",&a);
    if(a>=5000)
    b=a*0.6;
    else if(a>=2000)
    b=a*0.7;
    else if(a>=500)
    b=a*0.8;
    else if(a>=100)
    b=a*0.9;
    else
     b=a;
    printf("%.1f",b);
    return 0;
}