#include<stdio.h>
int main()
{
	double number;
	int num;
	double out=0;
	scanf("%lf",&number);
	num=number*10;
	while(num>0){
		out=out*10+num%10;
		num/=10;
	}
	 out=out/1000;
	 printf("%f",out);
	return 0;
}