import sys, heapq as hq

readline = sys.stdin.readline

ns = lambda: readline().rstrip()
ni = lambda: int(readline().rstrip())
nm = lambda: map(int, readline().split())
nl = lambda: list(map(int, readline().split()))

def k_shortestPath(G, s, t, k):
    N = len(G)
    d = [10**18]*N
    d[t] = 0
    p = [-1]*N
    q = [(0, t, t)]
    ret = list()
    while q:
        wei, src, dst = hq.heappop(q)
        if p[dst] >= 0: continue
        p[dst] = src
        for fdst, fwei in G[dst]:
            if d[fdst] > wei + fwei:
                d[fdst] = wei + fwei
                hq.heappush(q, (d[fdst], dst, fdst))
    l = 0
    R = [(0, -1, s)]
    while R:
        wei, src, dst = hq.heappop(R)
        if dst == t:
            ret.append(wei + d[s])
            l += 1
            if l == k:
                return ret
        for fdst, fwei in G[dst]:
            hq.heappush(R, (wei + fwei - d[dst] + d[fdst], dst, fdst))
    return None


def solve():
    n, m, k = nm()
    X, Y = nm()
    X -= 1; Y -= 1
    points = [tuple(nm()) for _ in range(n)]
    G = [list() for _ in range(n)]
    for _ in range(m):
        u, v = nm()
        u -= 1; v -= 1
        p, q = points[u]
        r, s = points[v]
        c = ((p - r)**2 + (q - s)**2) ** .5
        G[u].append((v, c))
        G[v].append((u, c))
    res = k_shortestPath(G, X, Y, k)
    print(*res, sep='\n')
    return

solve()