#include <stdio.h>
#include <string.h>
#include <math.h> 
int main(){
	int n,i,j,x[10000],y[20000];
	//double l[100000],rmin=1000000000;
	int l[100000],rmin=100000000000;
	scanf("%d",&n);	
	for(i=0;i<n;i++){
		scanf("%d %d",&x[i],&y[i]);
	} 
	for(i=0;i<n;i++){
	    //l[j++]=sqrt((x[i]-x[i+1])*(x[i]-x[i+1])+(y[i]-y[i+1])*(y[i]-y[i+1]))
	    int k=0;
	    for(j=0;j<n;j++){
	    	if(i!=j) 
	    	    //l[k++]=sqrt((x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]));
	    	    l[k++]=(x[i]-x[j])*(x[i]-x[j])+(y[i]-y[j])*(y[i]-y[j]);
		}
		double max=0;
		for(i=0;i<k;i++){
			if(max<l[i])max=l[i];
    	}
    	//double s=3.1415926535*max*max;	    
    	if(max<rmin)rmin=max;	
    }
	//printf("%.4lf",rmin*rmin*3.1415926535);
	printf("%.4lf",rmin*3.1415926535);
	return 0;
}