#include <bits/stdc++.h>
using namespace std;
using ll=long long;
const ll ILL=2167167167167167167;
const int INF=2100000000;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> int LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> int UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(b<a){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
    if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
    else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;}
template<class T> T square(T a){return a * a;}



void solve();
// DEAR MYSTERIES / TOMOO
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    ll N, S;
    cin >> N >> S;
    vector<ll> X(N), W(N + 1);
    rep(i, 0, N) cin >> X[i];
    rep(i, 0, N){
        cin >> W[i + 1];
        W[i + 1] += W[i];
    }
    vector dp(2, vector(N, vector<ll>(N, ILL)));
    dp[0][0][N - 1] = 0;
    dp[1][0][N - 1] = 0;
    rep(l, 0, N) for (int r = N - 1; r > l; r--){
        rep(k, 0, 2){
            ll pos = (k ? r : l);
            ll w = W[N] - W[r + 1] + W[l];
            w += W[pos + 1] - W[pos];
            pos = X[pos];
            if (k == 0) {
                chmin(dp[0][l + 1][r], dp[k][l][r] + w * abs(pos - X[l + 1]));
                chmin(dp[1][l + 1][r], dp[k][l][r] + w * abs(pos - X[r]));
            }
            else{
                chmin(dp[0][l][r - 1], dp[k][l][r] + w * abs(pos - X[l]));
                chmin(dp[1][l][r - 1], dp[k][l][r] + w * abs(pos - X[r - 1]));
            }
        }
    }
    ll ans = ILL;
    rep(k, 0, 2) rep(i, 0, N){
        chmin(ans, dp[k][i][i] + W[N] * abs(X[i] - S));
    }
    cout << ans << "\n";
}