#include <bits/stdc++.h>
using namespace std;
#define maxn 200005
#define int long long 
#define i128 __int128
int a[maxn],b[maxn];
int n,m;

bool check(int k){
    priority_queue<i128>pq;
    for(int i=1;i<=n;i++){
        pq.push((i128)a[i]*k);
    }
    for(int i=m-1;i>=0;i--){
        i128 cnt=b[i];
        i128 tmp=(1<<i);
        while(pq.size()&&pq.top()>=tmp&&cnt>0){
            int now=pq.top();
            pq.pop();
            i128 mm=min(now/tmp,cnt);
            now-=mm*tmp;
            cnt-=mm;
            if(now>0)pq.push(now);
        }
        while(pq.size()&&cnt--){
            pq.pop();
        }
    }
    return pq.empty();
}

void solve(){
    cin>>n>>m;
    for(int i=1;i<=n;i++){
        cin>>a[i];
    }
    for(int i=0;i<m;i++){
        cin>>b[i];
    }
    int l=1,r=1e11;
    while(l<=r){
        int mid=l+r>>1;
        if(check(mid)){
            l=mid+1;
        }
        else{
            r=mid-1;
        }
    }
    cout<<l-1<<'\n';

    
}

signed main(){
    ios::sync_with_stdio(0);
    cin.tie(0);
    int TT=1;cin>>TT;
    while(TT--){
        solve();
    }
}