n = int(input())
c = int(input())
v = int(input())
s = list(map(int, input().split()))
t = list(map(int, input().split()))
y = list(map(int, input().split()))
m = list(map(int, input().split()))

graph = [[] for _ in range(n)]
for i in range(v):
    graph[s[i] - 1].append([t[i] - 1, y[i], m[i]])

INF = 10**9
dp = [[INF for i in range(c+1)] for j in range(n)]
dp[0][0] = 0

for i in range(n):
    for j in range(c+1):
        if dp[i][j] == INF:
            continue
        for u in graph[i]:
            if u[1] + j > c:
                continue
            dp[u[0]][u[1] + j] = min(dp[u[0]][u[1] + j], dp[i][j] + u[2])
ans = min(dp[n-1])
if ans == INF:
    ans = -1
print(ans)