#include<cstdio>

 #include<cmath>

 #include<queue>

 #include<cstring>

 #include<string>

 #include<algorithm>

 #define CLR(a,b) memset((a),(b),sizeof((a)))

 using namespace std;

 typedef long long ll;

 const double inf = 0x3f3f3f3f;

 const int N = 2e5+;

 int n;

 struct Point{

     int x, y;

 }a[N], midp[N];

 double dis(Point a, Point b){

     return sqrt(.*(a.x - b.x)*(a.x - b.x) + .*(a.y - b.y)*(a.y - b.y));

 }

 bool cmp1(Point a, Point b){

     return a.x < b.x;

 }

 bool cmp2(Point a, Point b){

     return a.y < b.y;

 }

 double solve(int l, int r){

     if(l == r ||l +  == r) return inf;

     if(l +  == r) return dis(a[l],a[l+]) + dis(a[l+],a[r]) + dis(a[l],a[r]);

     int m = l + (r-l)/;

     double d1 = solve(l, m);

     double d2 = solve(m+, r);

     double d = min(d1, d2);

     double dd = d/2.0;

     double ans = d;

     int cnt = , i, j, k;

     for(i = l; i <= r; ++i)

         if(fabs(a[m].x - a[i].x) <= dd)

             midp[++cnt] = a[i];

     sort(midp+, midp++cnt, cmp2);

     for(i = ; i < cnt-; ++i){

         for(j = i+; j < cnt; ++j){

             if(midp[j].y - midp[i].y > dd)

                 break;

             for(k = j+; k <= cnt; ++k){

                 if(midp[k].y - midp[i].y > dd)

                     break;

                 double c = dis(midp[i],midp[j])+dis(midp[j],midp[k])+dis(midp[i],midp[k]);

                 ans = min(ans, c);

             }

         }

     }

     return ans;

 }

 int main(){

     scanf("%d", &n);

     for(int i = ; i <= n; ++i)

         scanf("%d%d", &a[i].x, &a[i].y);

     sort(a+, a++n, cmp1);

     printf("%.6lf\n", solve(,n));

     return ;

 }