#include<bits/stdc++.h>
using namespace std;
#define N 2005
#define ll long long
multiset<int>s;
int t,n,a[N];
ll b[N];
int main(){
    scanf("%d",&t);
    while (t--){
        scanf("%d",&n);
        for(int i=1;i<=n;i++)scanf("%d",&a[i]);
        ll sum=0;
        s.clear();
        for(int i=1;i<=n;i++){
            scanf("%lld",&b[i]);
            b[i]+=b[i-1];
            if (sum+a[i]<=b[i]){
                sum+=a[i];
                s.insert(a[i]);
            }
            else{
                if (!s.size())continue;
                set<int>::iterator it=(--s.end());
                if ((*it)>a[i]){
                    sum-=(*it)-a[i];
                    s.erase(it);
                    s.insert(a[i]);
                }
            }
        }
        printf("%d\n",s.size());
    }
}