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

int main(){
    ios::sync_with_stdio(false);
    cin.tie(0);
    int N, X, l = 0, r = 0;
    cin >> N >> X;
    vector<int> A(N), B(N);
    for(auto &v: A) cin >> v, v -= X;
    for(auto &v: B) cin >> v;
    int s = accumulate(B.begin(), B.end(), 0ll);
    vector<int> a(200 * N + 1, -(1 << 29));
    auto dp = a.begin() + 100 * N;
    dp[0] = 0;
    for(int i = 0; i < N; i++){
        if(A[i] >= 0){
            for(int j = r; j >= l; j--){
                dp[j + A[i]] = max(dp[j + A[i]], dp[j] + B[i]);
            }
            r += A[i];
        }else{
            for(int j = l; j <= r; j++){
                dp[j + A[i]] = max(dp[j + A[i]], dp[j] + B[i]);
            }
            l += A[i];
        }
    }
    int ans = 1 << 30;
    for(int i = r; i >= 0; i--) ans = min(ans, s - dp[i]);
    if(ans >= s) ans = -1;
    cout << ans << '\n';
}