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

ll dp[1001][1001][2];
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int n, s;
    cin >> n >> s;
    vector<int> x(n), w(n);
    for(auto &&v : x) cin >> v;
    for(auto &&v : w) cin >> v;
    vector<int> sv(n + 1);
    for(int i = 0; i < n; i++) sv[i + 1] = sv[i] + w[i];
    const ll W = sv[n];
    for(int i = 0; i < n; i++) dp[i][i + 1][0] = dp[i][i + 1][1] = W * abs(x[i] - s);
    for(int l = n - 2; l >= 0; l--){
        for(int r = l + 2; r <= n; r++){
            ll wl = W - (sv[r] - sv[l + 1]), wr = W - (sv[r - 1] - sv[l]);
            dp[l][r][0] = min(dp[l + 1][r][0] + wl * (x[l + 1] - x[l]), dp[l + 1][r][1] + wl * (x[r - 1] - x[l]));
            dp[l][r][1] = min(dp[l][r - 1][0] + wr * (x[r - 1] - x[l]), dp[l][r - 1][1] + wr * (x[r - 1] - x[r - 2]));
        }
    }
    cout << min(dp[0][n][0], dp[0][n][1]) << '\n';
}