def dfs(nowTown,money): if money < 0: return 9000000009 global N if nowTown >= N: return 0 global dp if dp[nowTown][money] != -1: return dp[nowTown][money] global S,T,Y,M,connect,time ret = 9000000009 for i in range(nowTown + 1,N + 1): if connect[nowTown][i] != -1: ret = min(ret,dfs(i,money - connect[nowTown][i]) + time[nowTown][i]) dp[nowTown][money] = ret return ret N,C,V = int(raw_input()),int(raw_input()),int(raw_input()) S,T,Y,M = map(int,raw_input().split()),map(int,raw_input().split()),map(int,raw_input().split()),map(int,raw_input().split()) connect = [[-1 for i in range(N + 1)] for j in range(N + 1)] time = [[-1 for i in range(N + 1)] for j in range(N + 1)] dp = [[-1 for i in range(300 + 2)] for j in range(N + 2)] for i in range(V): connect[S[i]][T[i]] = Y[i] time[S[i]][T[i]] = M[i] ans = dfs(1,C) if ans == 9000000009: print -1 else: print ans