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

#define M 1000000007
#define MM 998244353
#define ll long long
#define pb push_back
#define mem0(a) memset(a,0,sizeof(a))
#define mem1(a) memset(a,-1,sizeof(a))
#define memf(a) memset(a,false,sizeof(a))
#define all(v) v.begin(),v.end()
#define sz(a) (ll)a.size()
#define F first
#define S second
#define INF 2000000000000000000
#define endl "\n"
#define _time_ 1.0 * clock() / CLOCKS_PER_SEC
#define popcount(x) __builtin_popcountll(x)
#define pll pair<ll,ll>
#define ld long double

const long double PI = acos(-1);

ll power(ll b,ll e,ll m)
{
    if(e==0) return 1;
    if(e&1) return b*power(b*b%m,e/2,m)%m;
    return power(b*b%m,e/2,m);
}
ll power( ll b, ll e)
{
    if(e==0) return 1;
    if(e&1) return b*power(b*b,e/2);
    return power(b*b,e/2);
}
template<typename T, typename U> static inline void amin(T &x, U y){ if(y<x) x=y; }
template<typename T, typename U> static inline void amax(T &x, U y){ if(x<y) x=y; }
template<typename T, typename U> ostream& operator<<(ostream &os, const pair<T, U> &p)
{
    return os<<'('<<p.F<< ","<<p.S<<')';
}

const int N=100005,K=102;
ll dp[2][N];
ll h[K],s[K],k[K];
int _runtimeTerror_()
{
    int n,x;
    cin>>n>>x;
    for(int i=1;i<=n;++i)
        cin>>h[i];
    for(int i=1;i<=n;++i)
        cin>>s[i];
    for(int i=1;i<=n;++i)
        cin>>k[i];
    for(int i=1;i<=n;++i)
    {
        for(int j=0;j<h[i];++j)
        {
            dp[i%2][j]=dp[(i-1)%2][j];
            deque<pll> dq;
            dq.push_back({j,dp[i%2][j]});
            for(int l=j+h[i];l<=x;l+=h[i])
            {
                ll y=dp[(i-1)%2][l]-s[i]*(l-j)/h[i];
                while(!dq.empty() && dq.back().S<=y)
                    dq.pop_back();
                dq.push_back({l,y});
                while((l-dq.front().F)/h[i]>k[i])
                    dq.pop_front();
                dp[i%2][l]=dq.front().S+(l-j)/h[i]*s[i];
            }
        }
    }
    cout<<dp[n%2][x];
    return 0;
}

int main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    #ifdef runSieve
        sieve();
    #endif
    #ifdef NCR
        initialize();
    #endif
    int TESTS=1;
    //cin>>TESTS;
    while(TESTS--)
        _runtimeTerror_();
    return 0;
}