package tsp.cours.ci8;

class NegativeValue extends Exception {}

class Test {
	static double ln(double x) throws NegativeValue {
		if(x <= 0) { 
			throw new NegativeValue(); 
		} else { 
			return Math.log(x); 
		} 
	}

	public static void main(String[] args) {
		try { 
			double val = Double.parseDouble(args[0]);
			System.out.println(ln(val));
		} catch(NegativeValue v) {
			System.out.println("Chiffre positif attendu");
		} 
	} 
}