#include<stdio.h>
#include<cmath>
int main()
{
double a,b,c;
while(scanf("%lf",&a)==1)
{
b=round(100*a);
c=b/100;
if(c==-0.00)
printf("0.00\n");
else if(c==0.495)
printf("0.50\n");
else if(c==0.995)
printf("1.00\n");
else
printf("%.2f\n",c);
}
return 0;
}