#include <iostream>
#include <cmath>
#include <vector>

const double THIRD = 1/3;

using namespace std;

int main()
{
    int n;
    while ( cin >> n )
    {
        vector <pair <double,double> > points;
        double Max = 0;
        double lineA, lineB, lineC;
        for ( int i = 0 ; i < n ; i ++ )
        {
            double a, b;
            points . push_back ( pair<double,double>(a, b));
            cin >> a >> b;
            double x = cbrt((double)(a * b * b));
            double y = ( a * b ) / x;
            double val = sqrt ( ( a + x ) * ( a + x ) + ( b + y ) * ( b + y ) );

            if ( val > Max )
            {
                lineA = b+y;
                lineB = a+x;
                lineC = ( b * x + y * x);
                Max = val;
            }
        }
        bool fail = false;
        for ( unsigned int i = 0 ; i < points . size () ; i ++ )
        {
            if ( lineA * points [ i ] . first + lineB * points [ i ] . second + lineC <= 10e-4 )
            {
                fail = true;
                break;
                }
        }
        if ( fail )
        {
            for ( unsigned int i = 0 ; i < points . size () ; i ++ )
            {
                    lineA = points [ i ]. second;
                    lineB = points [ i ]. first;
                    lineC = - 2 * ( points [ i ] . first * points [ i ] . second );
                for ( unsigned int j = 0 ; j < points . size () ; j ++ )
                {
            if ( lineA * points [ i ] . first + lineB * points [ i ] . second + lineC <= 10e-4 )
            {
                continue;
                }
                Max = sqrt ( points [ i ] . first * points [ i ] . first + points [ i ] . second * points [ i ] . second );
                break;
                }
            }
        }
    cout << Max << endl;
    }
}