// tested by Hightail - https://github.com/dj3500/hightail
import std.stdio, std.string, std.conv, std.algorithm;
import std.range, std.array, std.math, std.typecons, std.container, core.bitop;

immutable inf = 10^^9 + 7;
int n, c, v;
int[] s, t, y, m;

void main() {
    scan(n);
    scan(c);
    scan(v);
    s = readln.split.to!(int[]);
    t = readln.split.to!(int[]);
    y = readln.split.to!(int[]);
    m = readln.split.to!(int[]);

    alias Road = Tuple!(int, "to", int, "y", int, "m");

    auto adj = new Road[][](n, 0);

    foreach (i ; 0 .. v) {
        adj[s[i] - 1] ~= Road(t[i] - 1, y[i], m[i]);
    }

    debug {
        //stderr.writeln(adj);
    }

    auto dp = new int[][](n, c + 1);
    foreach (i ; 0 .. n) {
        foreach (j ; 0 .. c + 1) {
            dp[i][j] = inf;
        }
    }
    dp[0][c] = 0;

    foreach (i ; 0 .. n) {
        foreach (j ; 0 .. c + 1) {
            if (dp[i][j] == inf) continue;
            foreach (v ; adj[i]) {
                if (j - v.y >= 0) dp[v.to][j - v.y] = min(dp[v.to][j - v.y], dp[i][j] + v.m);
            }

            debug {
                //writeln("dp:", dp);
            }
        }
    }

    int ans = dp[n - 1].minElement;

    if (ans == inf) {
        writeln(-1);
    }
    else {
        writeln(ans);
    }
}

void scan(T...)(ref T args) {
    string[] line = readln.split;
    foreach (ref arg; args) {
        arg = line.front.to!(typeof(arg));
        line.popFront();
    }
    assert(line.empty);
}