//A program that sometimes throws and exception and sometimes does not
#include <iostream>
#include <stdexcept>
#include <cmath>

using namespace std;

int main()
{
	try{
		double x;
		cout << "input a positive number: ";
		cin >> x;

		if( x<0 ) throw range_error("Input not positive");

		cout << "Square root of " << x << " = " << sqrt(x) << endl;
	}
	catch(exception &e)
	{
		cerr << e.what()<<endl;
		return 1;
	}

	return 0;
}