#include<stdio.h>
int main(void)
{
    int n;
    int s=0;
    float num;
    scanf("%.1f",&num);
    n=(int)(num*10);
    while(n!=0)
    {
        s=s*10+n%10;
        n=(int)(n/10);
    }
    printf("%.3f\n",(float)(s/1000));
    return 0;
}