from heapq import heapify as hpi , heappop as hpop , heappush as hpush
n,m,p,q,t=map(int,input().split())
g = [[] for i in range(n+1)]
for _ in range(m):
    x,y,z = map(int,input().split())
    g[x].append((y,z))
    g[y].append((x,z))

def  daiku(i):
    inf=float('inf')
    d = [inf for i in range(n+1)]
    d[i] = 0
    done=[0 for i in range(n+1)]
    hp=[]
    hpush(hp,(d[i],i))
    
    while hp:
        _ ,now= hpop(hp)
        if done[now]:
            continue
        done[now] = 1
        for go,cost in g[now]:
            if d[go] > d[now] + cost:
                d[go] = d[now] + cost
                hpush(hp,(d[go],go))

    return d

one=daiku(1)
ps=daiku(p)
qs=daiku(q)

ans = -1
if one[p]+ps[q]+qs[1] <= t:
    ans = t
for i in range(1,n+1):
    for j in range(1,n+1):
        tt=one[i] + max(ps[i]+ ps[j],qs[j] + qs[i]) +one[j]
        sepa=max(ps[i] + ps[j] , qs[i] + qs[j])
        if tt > t:
            continue
        ans=max(t-sepa,ans)

print(ans)