#include <iostream>
#include <math.h>
using namespace std;
int main()
{
int x,a,b,c;
double result;
cout << "Input x , a , b , c" << endl;
cin >> x >> a >> b >> c;
result = 1 / sqrt(a*pow(x, 2) + b * x + c);
cout << " Your result = " << result << endl;
}