#include<bits/stdc++.h>
using namespace std;


#define li          long long int
#define rep(i,to)   for(li i=0;i<((li)(to));i++)
#define repp(i,start,to)    for(li i=(li)(start);i<((li)(to));i++)
#define pb          push_back
#define sz(v)       ((li)(v).size())
#define bgn(v)      ((v).begin())
#define eend(v)     ((v).end())
#define allof(v)    (v).begin(), (v).end()
#define dodp(v,n)       memset(v,(li)n,sizeof(v))
#define bit(n)      (1ll<<(li)(n))
#define mp(a,b)     make_pair(a,b)
#define rin rep(i,n)
#define EPS 1e-12
#define ETOL 1e-8
#define MOD 1000000007
typedef pair<li, li> PI;

#define INF bit(60)

#define DBGP 1


#define idp if(DBGP)
#define F first
#define S second
#define p2(a,b)     idp cout<<a<<"\t"<<b<<endl
#define p3(a,b,c)       idp cout<<a<<"\t"<<b<<"\t"<<c<<endl
#define p4(a,b,c,d)     idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<endl
#define p5(a,b,c,d,e)       idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<endl
#define p6(a,b,c,d,e,f)     idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<endl
#define p7(a,b,c,d,e,f,g)       idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<"\t"<<g<<endl
#define p8(a,b,c,d,e,f,g,h)     idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<"\t"<<g<<"\t"<<h<<endl
#define p9(a,b,c,d,e,f,g,h,i)       idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<"\t"<<g<<"\t"<<h<<"\t"<<i<<endl
#define p10(a,b,c,d,e,f,g,h,i,j)        idp cout<<a<<"\t"<<b<<"\t"<<c<<"\t"<<d<<"\t"<<e<<"\t"<<f<<"\t"<<g<<"\t"<<h<<"\t"<<i<<"\t"<<j<<endl
#define foreach(it,v)   for(__typeof((v).begin()) it=(v).begin(); it!=(v).end(); ++it)
#define p2p(x)      idp p2((x).F, (x).S)
#define dump(x,n)   idp{rep(i,n){cout<<x[i]<<" ";}puts("");}
#define dump2(x,n)  idp{rep(i,n){cout<<"["<<x[i].F<<" , "<<x[i].S<<"] ";}puts("");}
#define dumpi(x)    idp{foreach(it, x){cout<<(*it)<<" ";}puts("");}
#define dumpi2(x)   idp{foreach(it, x){cout<<"["<<(it)->F<<" , "<<(it)->S<<"] ";}puts("");}

#define read2d(a,w,h)   rep(i,h)rep(j,w)cin>>a[i][j]
#define dump2d(a,w,h)   rep(i,h){rep(j,w)cout<<a[i][j]<<" ";puts("");}

typedef pair<li, li> PI;

PI p[55];
li n;

inline bool check(double x, double y, double r) {
    rin{
        if (hypot(x - p[i].F, y - p[i].S) > r + EPS) {
            return false;
        }
    }
    return true;
}

inline li dot(PI a, PI b) {
    return a.F * b.F + a.S * b.S;
}

inline bool oneline(PI a, PI b, PI c) {
    li dx1 = b.F - a.F;
    li dx2 = c.F - a.F;
    li dy1 = b.S - a.S;
    li dy2 = c.S - a.S;
    return dx1 * dy2 == dx2 * dy1;
}

PI operator*(li a, PI b) {
    return {a * b.F, a * b.S};
}

PI operator+(PI a, PI b) {
    return {a.F + b.F, a.S + b.S};
}

PI operator-(PI a, PI b) {
    return {a.F - b.F, a.S - b.S};
}

li operator*(PI a, PI b) {
    return a.F * b.F + a.S * b.S;
}

inline pair<double, double> calc(PI a, PI b, PI c) {
    li aa = (b - c) * (b - c);
    li bb = (c - a) * (c - a);
    li cc = (a - b) * (a - b);

    li t = aa * (bb + cc - aa);
    li u = bb * (cc + aa - bb);
    li w = cc * (aa + bb - cc);

    PI res_bunshi = (t * a + u * b + w * c);
    pair<double, double> res = {res_bunshi.F * 1.0 / (t + u + w),
                                res_bunshi.S * 1.0 / (t + u + w),
                               };
    return res;
}

int main() {
    cin >> n;

    rin{
        cin >> p[i].F >> p[i].S;
    }
    double res = 500000000.0;
    rin{
        repp(j, i + 1, n) {
            // chuuten
            double cx = (p[i].F + p[j].F) / 2.0;
            double cy = (p[i].S + p[j].S) / 2.0;
            double r = hypot(abs(p[i].F - p[j].F) / 2.0, abs(p[i].S - p[j].S) / 2.0);
            if (check(cx, cy, r)) {
                res = min(res, r);
            }
        }
    }

    rin{
        repp(j, i + 1, n) {
            repp(k, j + 1, n) {
                if (oneline(p[i], p[j], p[k])) {
                    continue;
                }
                pair<double, double> gaishin = calc(p[i], p[j], p[k]);
                double r = hypot(abs(gaishin.F - p[i].F), abs(gaishin.S - p[i].S));
                if (check(gaishin.F, gaishin.S, r)) {
                    res = min(res, r);
                }
            }
        }
    }


    printf("%.12f\n", res);

    return 0;
}

Measured memory_bytes: 256