#include <bits/stdc++.h>
using namespace std;
using ll = long long;

template <class T> std::vector<int> z_algorithm(const std::vector<T>& s) {
    int n = int(s.size());
    if (n == 0) return {};
    std::vector<int> z(n);
    z[0] = 0;
    for (int i = 1, j = 0; i < n; i++) {
        int& k = z[i];
        k = (j + z[j] <= i) ? 0 : std::min(j + z[j] - i, z[i - j]);
        while (i + k < n && s[k] == s[i + k]) k++;
        if (j + z[j] < i + z[i]) j = i;
    }
    z[0] = n;
    return z;
}
std::vector<int> z_algorithm(const std::string& s) {
    int n = int(s.size());
    std::vector<int> s2(n);
    for (int i = 0; i < n; i++) {
        s2[i] = s[i];
    }
    return z_algorithm(s2);
}

class LiChaoTree{
    struct Line{
        long long a, b;
        long long get(long long x){return a * x + b; }
        Line(long long a, long long b) : a(a), b(b) {}
    };
    struct Node {
        Node *left, *right;
        Line line;
        Node(Line line) : left(nullptr), right(nullptr), line(line) {}
    };
    const long long inf = 1ll << 60;
    const Line inf_line = Line{0, inf};

    Node *root;
    long long lx, rx;
    Node* _add_line(Node *nd, Line line, long long l, long long r){
        if(l == r) return nullptr;
        if(nd == nullptr) return new Node(line);
        long long m = (l + r) >> 1;

        bool left = (line.get(l) <= nd->line.get(l));
        bool mid = (line.get(m) <= nd->line.get(m));
        bool right = (line.get(r) <= nd->line.get(r));
        if(left && right)nd->line = line;
        if(left == right)return nd;
        if(mid) std::swap(nd->line, line);
        if(left != mid){
            nd->left = _add_line(nd->left, line, l, m);
        }else{
            nd->right = _add_line(nd->right, line, m, r);
        }
        return nd;
    }
    Node* _add_segment_line(long long a, long long b, Node *nd, Line line, long long l, long long r) {
        if(r <= a || b <= l) return nd;
        if(a <= l && r <= b) return _add_line(nd, line, l, r);
        if(nd == nullptr) nd = new Node(inf_line);
        long long m = (l + r) >> 1;
        nd->left = _add_segment_line(a, b, nd->left, line, l, m);
        nd->right = _add_segment_line(a, b, nd->right, line, m, r);
        return nd;
    }
    long long query(long long x, long long l, long long r){
        Node *nd = root;
        long long res = inf;
        while(r > l && nd != nullptr) {
            long long m = (l + r) >> 1;
            res = std::min(res, nd->line.get(x));
            if(x < m) {
                r = m;
                nd = nd->left;
            } else {
                l = m;
                nd = nd->right;
            }
        }
        return res;
    }
    public:
    // [xl, xr)
    LiChaoTree(long long lx, long long rx) : lx(lx), rx(rx), root(nullptr) {}
    void add_line(long long a, long long b) {
        Line line(a, b);
        root = _add_line(root, line, lx, rx);
    }
    void add_segment_line(long long a, long long b, long long l, long long r) {
        Line line = Line{a, b};
        root = _add_segment_line(l, r, root, line, lx, rx);
    }
    long long get(long long x) {
        return query(x, lx, rx);
    }
};


int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    vector<ll> a(n), b(m), c(m);
    for(auto &&v : a) cin >> v;
    for(auto &&v : b) cin >> v;
    for(auto &&v : c) cin >> v;
    a.emplace_back(-1);
    a.insert(a.end(), b.begin(), b.end());
    auto z = z_algorithm(a);
    LiChaoTree LT(0, m + 1);
    n++;
    LT.add_segment_line(0, 0, 0, 1);
    for(int i = 0; i < m; i++){
        if(z[i + n] == 0) continue;
        ll v = LT.get(i);
        LT.add_segment_line(c[i], -c[i] * i + v, i, i + z[i + n] + 1);
    }
    ll ans = LT.get(m);
    if(ans >> 60) ans = -1;
    cout << ans << '\n';
}