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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    ll N, X;
    cin >> N >> X;
    vector<ll> A(N), B(N);
    for(auto &v: A)cin >> v, v -= X;
    for(auto &v: B)cin >> v;
    ll s = accumulate(B.begin(), B.end(), 0ll);
    vector<ll> a(200 * N + 1, -(1ll << 60));
    auto dp = a.begin() + 100 * N;
    dp[0] = 0;
    for(int i = 0; i < N; i++){
        if(A[i] >= 0){
            for(int j = 100 * i; j >= -100 * i; j--){
                dp[j + A[i]] = max(dp[j + A[i]], dp[j] + B[i]);
            }
        }else{
            for(int j = -100 * i; j <= 100 * i; j++){
                dp[j + A[i]] = max(dp[j + A[i]], dp[j] + B[i]);
            }
        }
    }
    ll ans = 1ll << 60;
    for(int i = 100 * N; i >= 0; i--) ans = min(ans, s - dp[i]);
    if(ans >= s) ans = -1;
    cout << ans << '\n';
}