gistfile1.cpp

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

double truncate(long double number, int n)
{
	return (int)(number*pow(10,n)) / (float)pow(10,n);
}

long double get_consumption(double a, double b, double c, double d, double v)
{
	return a*pow(v,3) + b*pow(v,2) + c*v + d;
}

double max_velocity(double a,double b, double c, double d, double start, double end,double max_consumption)
{
	/*cout << "start:  " << start << endl;
	cout << "end:  " << end << endl;*/
	double temp;
	double new_v = (start + end) / 2;
	//if((temp = truncate(new_v,3)) == truncate(start,3) or temp == truncate(end,3))
	if(abs(new_v - start) < 10e-6 or abs(new_v - end) < 10e-6)
	{
		// cout << "temp:  " << temp << endl;
		// cout << "start:  " << truncate(start,3) << endl;
		// cout << "end:  " << truncate(end,3) << endl;
		//return truncate(temp,2);
		return truncate(new_v,2);
	}
	else
	{
		double start_consumption = get_consumption(a,b,c,d,start) - max_consumption;
		double new_consumption = get_consumption(a,b,c,d,new_v) - max_consumption;
		double end_consumption = get_consumption(a,b,c,d,end) - max_consumption;
		if((start_consumption > 0 and new_consumption < 0) or (start_consumption < 0 and  new_consumption > 0))
		//cout << "fuck:" << endl;
		//cout << abs(start_consumption - end_consumption) << endl;
		//if(abs(start_consumption - end_consumption) < pow(10,-6))
			return max_velocity(a,b,c,d,start,new_v,max_consumption);
		else
		//if((new_consumption > 0 and end_consumption < 0) or (new_consumption < 0 and  end_consumption > 0))
			return max_velocity(a,b,c,d,new_v,end,max_consumption);
		/*else
			return max_velocity(a,b,c,d,start,new_v,max_consumption);*/
	}
}

int main()
{
	double a,b,c,d,m,t;
	while(cin >> a >> b >> c >> d >> m >> t)
		cout << max_velocity(a,b,c,d,0,pow(10,6),t/m) << endl;
}