0101-ComputSQRT

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

int main()
{
    double n,r,guess,pre_guess;
    while(cin>>n)
    {
        guess=n/2;
        do{
            r=n/guess;
            pre_guess=guess;
            guess=(guess+r)/2; 
        }while(pre_guess-guess>=0.01);
        cout << fixed << setprecision(2) << guess << endl;
    }
    return 0;
}