
#include <stdio.h>
int main()
{
float fw;
int w,t,fy=10;
scanf("%f",&fw);
w = fw;
if(fw - w > 0)
w++;
t = w/10;
switch(t)
{
default:
{
fy += (w-30)*6;
w = 30;
}
case 1:
case 2:
{
fy += (w-10)*5;
w = 10;
}
case 0:
{
fy += (w-1)*4;
}
}
printf("%d",fy);
return 0;
}
int main()
{
float w=0.f,money=0.f;
scanf("%f",&w);
if(w-(float)(int)w)
w=(float)((int)w+1);
while(w)
{
if(w<=10.f)
{
money = money + 10.f + (w-1.0f)*4.0f;
w=0.f;
}else if(10.f<w && w<=30.f)
{
money = money + (w-10.f)*5.0f;
w=10.f;
}else{
money = money + (w-30.f)*6.0f;
w=30.f;
}
}
printf("%.2f",money);
return 0;
}