import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################

N = ni()
C = ni()
V = ni()
S = na()
T = na()
Y = na()
M = na()
G = [[] for i in range(N)]

for i in range(V):
    S[i] -= 1
    T[i] -= 1
    G[S[i]].append((T[i], Y[i], M[i]))
dist = [[float("inf")for j in range(C+1)]for i in range(N)]

for i in range(C+1):
    dist[0][i] = 0

for i in range(N):
    for j in range(C+1):
        now = dist[i][j]
        for t, y, m in G[i]:
            nj = j + y
            if nj > C:
                continue
            dist[t][nj] = min(dist[t][nj], now + m)
if min(dist[-1])==float("inf"):
    print(-1)
else:
    print(min(dist[-1]))