#include <iostream>
#include <cmath>

const double THIRD = 1/3;

using namespace std;

int main()
{
    int n;
    while ( cin >> n )
    {
        double Max = 0;
        for ( int i = 0 ; i < n ; i ++ )
        {
            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 )
                Max = val;
        }
    cout << Max << endl;
    }
}