#include <iostream>
#include <vector>
#include <cmath>
using namespace std;
struct	point2D
{
	int x;
	int y;
};
float	max(float a, float b)
{
	if (a>b)
		return a;
	else 
		return b;
}
void	inputPoint(vector<point2D> point)
{
	int i;
	int n;
	point2D temp;
	cout << "Hay nhap so diem: ";
	cin >> n;
	point.resize(n);
	for (i=1;i<=(n);i++)
	{
		cout << "Hay nhap diem thu " << i << endl ;
		cin >> temp.x >> temp.y;
		point.push_back(point2D());  //emplace_back()
		point[i-1].x=temp.x;
		point[i-1].y=temp.y;
	}
	cout << "Complete";
}
float	distance(point2D pt1, point2D pt2)
{
	return sqrt(pow(double(pt1.x-pt2.x),2)+pow(double(pt1.y-pt2.y),2));
}
float	findDis(vector<point2D> point)
{
	int size=point.size();
	float maximum=0;
	int i,j;
	for (i=0;i<size;i++)
		for (j=0;j<size;i++)
			maximum=max(maximum,distance(point[i],point[j]));
	return	maximum;
}

int main()
{
	vector<point2D> point;
	int n;
	inputPoint(point);
	cout << "Khoang cach lon nhat la: " << findDis(point);
	getchar();
	getchar();
	return 0;
}