#include "bits/stdc++.h"
using namespace std;
#define FOR(i,j,k) for(int (i)=(j);(i)<(int)(k);++(i))
#define rep(i,j) FOR(i,0,j)
#define each(x,y) for(auto &(x):(y))
#define mp make_pair
#define all(x) (x).begin(),(x).end()
#define debug(x) cout<<#x<<": "<<(x)<<endl
#define smax(x,y) (x)=max((x),(y))
#define smin(x,y) (x)=min((x),(y))
#define MEM(x,y) memset((x),(y),sizeof (x))
#define sz(x) (int)(x).size()
typedef long long ll;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<ll> vll;

const ll INF = numeric_limits<ll>::max();
ll N, M, A[500], K[500];

void solve(){
    ll r = -M;
    rep(i, N)r += A[i] * K[i];
    if(r < 0){
        puts("-1");
        return;
    }
    
    ll ans = 0;
    if(r >= A[N - 1] * A[N - 1]){
        ans += (r-A[N-1]*A[N-1]) / A[N-1];
        r -= ans * A[N-1];
    }

    vll dp(r+1, INF);
    dp[0] = ans;
    rep(i, N){
        ll a = A[i], m = r / a;
        for(ll x = 1; m; x <<= 1){
            ll y = min(m, x);
            m -= y;
            for(int j = (int)r; j >= 0; --j)if(dp[j]!=INF && j + y*a <= r){
                smin(dp[j + y*a], dp[j] + y);
            }
        }
    }
    cout << (dp.back() == INF ? -1 : dp.back()) << endl;
}

int main(){
    while(cin >> N >> M){
        rep(i, N)scanf("%lld", &A[i]);
        rep(i, N)scanf("%lld", &K[i]);
        solve();
    }
}