#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<vector>
#include<cmath>
#include<set>
using std::set;
using std::sort;
using std::pair;
using std::swap;
using std::multiset;
#define pb(e) push_back(e)
#define sz(c) (int)(c).size()
#define mp(a, b) make_pair(a, b)
#define all(c) (c).begin(), (c).end()
#define iter(c) decltype((c).begin())
#define cls(arr, val) memset(arr, val, sizeof(arr))
#define cpresent(c, e) (find(all(c), (e)) != (c).end())
#define rep(i, n) for(int i = 0; i < (int)n; i++)
#define tr(c, i) for(iter(c) i = (c).begin(); i != (c).end(); ++i)
const int N = 1010;
const int INF = 0x3f3f3f3f;
typedef unsigned long long ull;
struct Node {
	int x, y;
	double w;
	Node() {}
	Node(int i, int j, double k) :x(i), y(j), w(k) {}
	inline bool operator<(const Node &t) const {
		return w < t.w;
	}
}G[(N * N) << 1];
struct P {
	double x, y;
	inline double calc(const P &t) const {
		return sqrt((x - t.x) * (x - t.x) + (y - t.y) * (y - t.y));
	}
}A[N];
struct Kruskal {
	int E, par[N], rank[N];
	inline void init() {
		E = 0;
		rep(i, N) {
			par[i] = i;
			rank[i] = 0;
		}
	}
	inline int find(int x) {
		while (x != par[x]) {
			x = par[x] = par[par[x]];
		}
		return x;
	}
	inline bool unite(int x, int y) {
		x = find(x), y = find(y);
		if (x == y) return false;
		if (rank[x] < rank[y]) {
			par[x] = y;
		} else {
			par[y] = x;
			rank[x] += rank[x] == rank[y];
		}
		return true;
	}
	inline void built(int n, int m) {
		int u, v;
		for(int i = 1; i<= n; i++) scanf("%lf %lf", &A[i].x, &A[i].y);
		for (int i = 1; i <= n; i++) {
			for (int j = i + 1; j <= n; j++) {
				G[E++] = Node(i, j, A[i].calc(A[j]));
			}
		}
		while (m--) {
			scanf("%d %d", &u, &v);
			G[E++] = Node(u, v, 0.0);
		}
	}
	inline double kruskal(int n) {
		int tot = 0;
		double ans = 0.0;
		sort(G, G + E);
		rep(i, E) {
			Node &e = G[i];
			if (unite(e.x, e.y)) {
				ans += e.w;
				if (++tot >= n - 1) return ans;
			}
		}
		return -1.0;
	}
	inline void solve(int n, int m) {
		init(), built(n, m);
		printf("%.2lf\n", kruskal(n));
	}
}go;
int main() {
#ifdef LOCAL
	freopen("in.txt", "r", stdin);
	freopen("out.txt", "w+", stdout);
#endif
	int n, m;
	while (~scanf("%d %d", &n, &m)) {
		go.solve(n, m);
	}
	return 0;
}