1063 计算谱半径

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

int main()
{
    int n;
    cin>>n;
    int a[n],b[n];
    double pu=0;
    for(int i=0;i<n;i++)
    {
        cin>>a[i]>>b[i];
        if(a[i]*a[i]+b[i]*b[i]>pu*pu)
        {
            pu=sqrt(a[i]*a[i]+b[i]*b[i]);
        }
    }
    cout<<fixed<<setprecision(2)<<pu;
    return 0;
}