#include<stdio.h>
int main(){
    double x,f;
    scanf("%lf",&x);
    if(x<=150){
        f=x*0.4463;
    }else if(x>=151&&x<=400){
        f=150*0.4463+(x-150)*0.4663;
    }else{
        f=150*0.4463+250*0.4663+(x-400)*0.5663;
    }
    printf("%.1lf",f+0.05);
    return 0;
}