#include<iostream>
#include<vector>
#include<algorithm>

using namespace std;
using ll = long long;


int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    int t;
    cin>>t;
    vector<int> dp(t+1,0);
    int n;
    cin>>n;
    vector<int> c(n),v(n);
    for(int i = 0;i<n;i++) cin>>c[i];
    for(int i = 0;i<n;i++) cin>>v[i];
    for(int i = 0;i<n;i++){
        while(v[i]>0){
            for(int j = t;j>=0;j--){
                if(j-c[i]<0) continue;
                dp[j] = max(dp[j],dp[j-c[i]]+v[i]);
            }
            v[i] /= 2;
        }
    }
    int mx = 0;
    for(int i = 0;i<=t;i++) mx = max(mx,dp[i]);
    cout<<mx<<endl;
}