#include <map>#include <set>#include <list>#include <cmath>#include <ctime>#include <deque>#include <stack>#include <queue>#include <cctype>#include <cstdio>#include <string>#include <vector>#include <climits>#include <cstdlib>#include <cstring>#include <iostream>#include <algorithm>#define LL long long#define PI 3.1415926535897932626using namespace std;int gcd(int a, int b) {return a % b == 0 ? b : gcd(b, a % b);}#define MAXN 755int p[MAXN];int N,M,cas;int Find(int x) {return x == p[x] ? x : p[x] = Find(p[x]);}struct node{    int x,y;}src[MAXN];struct dis{    int u,v;    double dist;    friend bool operator < (const dis &a,const dis &b)    {        return a.dist < b.dist;    }}d[MAXN*MAXN];void read(){    cas = 0;    for (int i = 1; i <= N; i++)        scanf("%d%d",&src[i].x,&src[i].y);    for (int i = 1; i <= N; i++)        for (int j = i + 1; j <= N; j++)    {        d[cas].u = i;        d[cas].v = j;        d[cas++].dist = sqrt((double)((src[j].x - src[i].x) * (src[j].x - src[i].x)) + (double)((src[j].y - src[i].y) * (src[j].y - src[i].y)));    }    sort(d,d + cas);    scanf("%d",&M);    for (int i = 0; i <= N; i++) p[i] = i;    while (M--)    {        int u,v;        scanf("%d%d",&u,&v);        int x = Find(u) , y = Find(v);        if (x != y) p[x] = y;    }}double kruskal(){    double ans = 0;    for (int i = 0; i < cas; i++)    {        int u = d[i].u , v = d[i].v ;        double w = d[i].dist;        int x = Find(u) , y = Find(v);        if (x != y)        {            ans += w;            p[x] = y;        }    }    return ans;}int main(){    while (scanf("%d",&N) != EOF)    {        read();        printf("%.2lf\n",kruskal());    }    return 0;}