#include <iostream>
#include <cmath>
using namespace std;

double Fa(double x) {
	return pow(x,3)+5*x-3;
}

main() {
	double p = -2, q=2, L = 100;
	double s = (p+q)/2;
	do {
		L--;
		s=(p+q)/2;
		if(Fa(p)*Fa(s)>0) {
			p=s;
		} else {
			q=s;
		}

	} while(Fa(p) != 0 && Fa(q) != 0 && L>0);
	if(Fa(p) == 0 || Fa(q) == 0) {
		cout<<p;
		exit(123);
	}
	cout<<"S: "<<s;
}