#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <cmath>

#include <set>
#include <bitset>
#include <map>
#include <string>
#include <algorithm>
#include <vector>
#include <iostream>
#include <queue>

using namespace std;

#define maxn 3010
#define mlog 16
#define F(i,j,k) for (int i=j;i<=k;++i)
#define inf (0x3f3f3f3f)

int Getint()
{
    int x=0,f=1; char ch=getchar();
    while (ch<‘0‘||ch>‘9‘) {if (ch==‘-‘) f=-1; ch=getchar();}
    while (ch>=‘0‘&&ch<=‘9‘) {x=x*10+ch-‘0‘; ch=getchar();}
    return x*f;
}

struct edge{int l,r;double d;}e[maxn*maxn];
struct Point{int x,y;}a[maxn];
int n,cnt=0;
bool cmp(edge x,edge y){return x.d>y.d;}
bitset <maxn> b[maxn];

int main()
{
	n=Getint();
	F(i,1,n)
	{
		a[i].x=Getint();
		a[i].y=Getint();
	}
	F(i,1,n-1)
		F(j,i+1,n)
		{
			e[++cnt].l=i;
			e[cnt].r=j;
			e[cnt].d=sqrt((a[i].x-a[j].x)*(a[i].x-a[j].x)+(a[i].y-a[j].y)*(a[i].y-a[j].y));
		}
	sort(e+1,e+cnt+1,cmp);
	F(i,1,cnt)
	{
		if ((b[e[i].l]&b[e[i].r]).count())
		{
			printf("%.20f\n",e[i].d/2);
			return 0;
		}
		b[e[i].l][e[i].r]=1;
		b[e[i].r][e[i].l]=1;
	}
}