# coding:utf-8 def int0(n): return int(n)-1 N = int(input()) # 街の数 C = int(input()) # 所持金 V = int(input()) # 道の数 S = list(map(int0, input().split())) # S->T T = list(map(int0, input().split())) # Y = list(map(int, input().split())) # cost[S][T] M = list(map(int, input().split())) # time[S][T] cost = [[301 for _ in range(N)] for _ in range(N)] time = [[50*1001 for _ in range(N)] for _ in range(N)] for i in range(V): cost[S[i]][T[i]] = Y[i] time[S[i]][T[i]] = M[i] for i in range(N): for j in range(i, N): for k in range(j, N): if time[i][j] > time[i][k]+time[k][j]: if cost[i][k]+cost[k][j]<=C: time[i][j] = time[i][k]+time[k][j] cost[i][j] = cost[i][k]+cost[k][j] ans = [] for j in range(N): if time[0][j] == 50050: continue ans.append(time[0][j]) print(max(ans))