#include <algorithm>
#include <iostream>
#include <iomanip>
#include <limits.h>
#include <map>
#include <math.h>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <string>
#include <utility>
#include <vector>
#include <stack>
#include <complex>
#include <array>
#include <cassert>
#include <random>

using namespace std;
#define rep(i, n) for (int i = 0; i < n; i++)
#define all(A) A.begin(), A.end()
#define debug(var) cout << #var << " = " << var << endl;
typedef long long ll;

template <typename T1, typename T2>
ostream &operator<<(ostream &os, const pair<T1, T2> &p)
{
    os << "(" << p.first << "," << p.second << ")";
    return os;
}

template <typename T1, typename T2>
istream &operator>>(istream &is, pair<T1, T2> &p)
{
    is >> p.first >> p.second;
    return is;
}

template <typename T>
ostream &operator<<(ostream &os, const vector<T> &v)
{
    for (int i = 0; i < (int)v.size(); i++)
    {
        os << v[i] << (i + 1 != (int)v.size() ? " " : "");
    }
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, const vector<vector<T>> &v)
{
    for (int i = 0; i < (int)v.size(); i++)
    {
        os << v[i] << endl;
    }
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, const vector<vector<vector<T>>> &v)
{
    int n = v.size();
    int m = v[0].size();
    int p = v[0][0].size();
    rep(k, p)
    {
        os << "k = " << k << endl;
        rep(i, n)
        {
            rep(j, m)
            {
                os << v[i][j][k];
                if (j < m - 1)
                {
                    os << " ";
                }
                else
                {
                    os << endl;
                }
            }
        }
    }
    return os;
}

template <typename T>
istream &operator>>(istream &is, vector<T> &v)
{
    for (T &in : v)
        is >> in;
    return is;
}

template <typename T, typename S>
ostream &operator<<(ostream &os, map<T, S> &mp)
{
    for (auto &[key, val] : mp)
    {
        os << key << ":" << val << " ";
    }
    cout << endl;
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, set<T> st)
{
    auto itr = st.begin();
    for (int i = 0; i < (int)st.size(); i++)
    {
        os << *itr << (i + 1 != (int)st.size() ? " " : "");
        itr++;
    }
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, multiset<T> st)
{
    auto itr = st.begin();
    for (int i = 0; i < (int)st.size(); i++)
    {
        os << *itr << (i + 1 != (int)st.size() ? " " : "");
        itr++;
    }
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, queue<T> q)
{
    while (q.size())
    {
        os << q.front() << " ";
        q.pop();
    }
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, deque<T> q)
{
    while (q.size())
    {
        os << q.front() << " ";
        q.pop_front();
    }
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, stack<T> st)
{
    while (st.size())
    {
        os << st.top() << " ";
        st.pop();
    }
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, priority_queue<T> pq)
{
    while (pq.size())
    {
        os << pq.top() << " ";
        pq.pop();
    }
    return os;
}

template <typename T>
ostream &operator<<(ostream &os, priority_queue<T, vector<T>, greater<T>> mpq)
{
    while (mpq.size())
    {
        os << mpq.top() << " ";
        mpq.pop();
    }
    return os;
}

int main(){
    int n,s;
    cin >> n >> s;
    vector<int> x(n);
    cin >> x;
    vector<int> w(n);
    cin >> w;
    vector<int> buc(1e3+1);
    int total = 0;
    rep(i,n){
        buc[x[i]] = w[i];
        total += w[i];
        assert(x[i]!=s);
    }
    vector<int> left,right;
    rep(i,n){
        if(x[i]<s){
            left.push_back(x[i]);
        }else{
            right.push_back(x[i]);
        }
    }
    reverse(all(right));
    int L = left.size();
    int R = right.size();
    vector<int> imos_L(L+1);
    vector<int> imos_R(R+1);
    rep(i,L){
        imos_L[i+1] = imos_L[i]+buc[left[i]];
    }
    rep(i,R){
        imos_R[i+1] = imos_R[i]+buc[right[i]];
    }
    // debug(left);
    // debug(right);
    // debug(imos_L);
    // debug(imos_R);
    using VI = vector<int>;
    using VVI = vector<VI>;
    using VVVI = vector<VVI>;
    using VVVVI = vector<VVVI>;
    using VVVVVI = vector<VVVVI>;
    VVVI dp(L+1,VVI(R+1,VI(2,1e9)));
    if(L){
        dp[1][0][0] = 0;
    }
    if(R){
        dp[0][1][1] = 0;
    }
    auto chmin=[](auto& a, const auto& b){
        if(b<a){
            a=b;
            return true;
        }
        return false;
    };
    rep(i,L+1){
        rep(j,R+1){
            rep(side,2){
                if(dp[i][j][side]==1e9){
                    continue;
                }
                int pos;
                int weight = imos_L[i]+imos_R[j];
                int current = dp[i][j][side];
                if(side==0){
                    pos = left[i-1];
                }else{
                    pos = right[j-1];
                }
                if(i<L){
                    int dist = abs(pos-left[i]);
                    chmin(dp[i+1][j][0],current+weight*dist);
                }
                if(j<R){
                    int dist = abs(pos-right[j]);
                    chmin(dp[i][j+1][1],current+weight*dist);
                }
            }
        }
    }
    // cout << dp << endl;
    int left_ans = 1e9;
    int right_ans = 1e9;
    if(L){
        left_ans = dp[L][R][0]+total*abs(s-left.back());
    }
    if(R){
        right_ans = dp[L][R][1]+total*abs(s-right.back());
    }
    // debug(left_ans);
    // debug(right_ans);
    int ans = min(left_ans,right_ans);
    cout << ans << endl;
}