#include <iostream>
#include <cstdio>
#include <fstream>
#include <algorithm>
#include <cmath>
#include <deque>
#include <vector>
#include <queue>
#include <string>
#include <cstring>
#include <map>
#include <stack>
#include <set>
#include <sstream>

using namespace std;

typedef long long ll;
typedef long double ld;

#define mp make_pair
#define pb push_back
#define FOR(i,a,x) for(int i=(a);i<(x);i++)
#define rep(i,n)	FOR(i,0,n)
#define xFOR(i,a,x) for(int i=(a);i<=(x);i++)
#define sor(v) sort(v.begin(),v.end())
#define rev(s) reverse(s.begin(),s.end())
#define lb(vec,a) lower_bound(vec.begin(),vec.end())
#define ub(vec,a) upper_bound(vec.begin(),vec.end())
#define uniq(vec) vec.erace(unique(vec.begin(),vec.end(),vec.end))
#define mp1(a,b,c) P1(a,P(b,c))
#define all(x) (x).begin(),(x).end()

#define debug(X) cout<<"["<<#X<<"]"<<X<<endl;



inline bool cheak(int x, int y, int xMax, int yMax) { return x >= 0 && y >= 0 && xMax > x && yMax > y; }
inline int toInt(string s) { int v; istringstream sin(s); sin >> v; return v; }
template<class T> inline string toString(T x) { ostringstream sout; sout << x; return sout.str(); }
template<class T> inline T sqr(T x) { return x*x; }


const int dx[8] = { 1, 0, -1, 0, 1, 1, -1, -1 }, dy[8] = { 0, -1, 0, 1, -1, 1, -1, 1 };
const int mod = 1000000007;
const int INF = 1e9;

#define MAX_V 1500

int n, c, v;
int s[MAX_V+10], t[MAX_V+10], y[MAX_V+10], m[MAX_V+10];
//dp[町の番号][残りのお金]=経過時間
int dp[51][301];
int main() {
	cin >> n >> c >> v;
	rep(i, v)cin >> s[i];
	rep(i, v)cin >> t[i];
	rep(i, v)cin >> y[i];
	rep(i, v)cin >> m[i];

	rep(i, 51) {
		rep(j, 301) {
			dp[i][j] = -1;
		}
	}
	dp[1][c] = 0;
	for (int i = 0; i < v; i++) {
		if (c - y[i] > 0)
			dp[t[i]][c - y[i]] = dp[s[i]][c] + m[i];
		else
			continue;
	}
	int ans=INF;
	for (int i = 0; i <= c; i++) {
		if (dp[n][i] == -1)continue;
		if (ans > dp[n][i])ans = dp[n][i];
	}
	if (ans != INF)cout << ans << endl;
	cout << "-1" << endl;
	return 0;
}