P49

#include <iostream>
#include <fstream>
using namespace std;
double y(double x)
{
	if ((x>=0)&&(x!=1)) return (-1/(1-x));
	else if ((x<0)&&(x!=-1)) return (1/(1+x));
	else return 1;
}
int main (void)
{
	ifstream ins("p49.txt");
	ofstream ous("ans49.txt");
	double a,b,h;
	ins >> a >> b >> h;
	for (double i=a; i<=b; i+=h)
		ous << i << " " << y(i) << endl;
}