#include<iostream>
#include<cmath>
#define PI 3.1415926535
using namespace std;

int n;
double ans = 0x3f3f3f3f;
struct location{
	double x,y;
}loc[1005];

int main(){
	cin>>n;
	for(int i = 0;i < n;i ++)
		cin>>loc[i].x>>loc[i].y;
	for(int i = 0;i < n;i ++){
		double sum;
		for(int j = 0;j < n;j ++){
			if(i != j){
				double tmp = sqrt(pow(abs(loc[i].x - loc[j].x) ,2) + pow(abs(loc[i].y - loc[j].y),2));
				sum = max(tmp,sum);
			}
			ans = min(ans,sum);
		}
	}
	printf("%.4lf",pow(ans,2) * PI);
	return 0;
}