import sys

def MI(): return map(int, sys.stdin.readline().split())

def main():
    inf=10**16
    n,m,k,s,t=MI()
    to=[[] for _ in range(n-1)]
    for _ in range(m):
        a,b,c=MI()
        to[a-1].append((b,c))

    dp={s:0}
    for i in range(n-1):
        if not to[i]:
            print(-1)
            exit()
        ndp={}
        for b,c in to[i]:
            ndp[c]=inf
            for f, v in dp.items():
                ndp[c]=min(ndp[c],v+abs(f-b))
        dp=ndp

    ans=inf
    for f,v in dp.items():
        ans=min(ans,v+abs(f-t))

    print(ans)

main()