#include<bits/stdc++.h>
#define fo(i,a,b) for(int i=a;i<=b;++i)
#define fod(i,a,b) for(int i=a;i>=b;--i)
#define max(q,w) ((q)>(w)?(q):(w))
#define min(q,w) ((q)<(w)?(q):(w))
using namespace std;
typedef long long LL;
const int N=2050;
const LL INF=1e18;
int read(int &n)
{
    int q=1;n=0;char ch=' ';
    for(;ch!='-'&&(ch<'0'||ch>'9');ch=getchar());
    if(ch=='-')q=-1,ch=getchar();
    for(;ch<='9'&&ch>='0';ch=getchar())n=(n<<1)+(n<<3)+ch-48;
    return n;
}
int n,m,ans;
int a[N];
LL b[N];
LL f[N][N];
int main()
{
    int q,w,_;
    read(_);
    while(_--)
    {
        read(n);
        fo(i,1,n)read(a[i]);
        fo(i,1,n)b[i]=b[i-1]+read(q);
        fo(i,0,n)fo(j,0,n)f[i][j]=INF;
        f[0][0]=ans=0;
        fo(i,0,n-1)fo(j,0,i)if(f[i][j]<INF)
        {
            ans=max(ans,j);
            f[i+1][j]=min(f[i+1][j],f[i][j]);
            if(f[i][j]+a[i+1]<=b[i+1])f[i+1][j+1]=min(f[i+1][j+1],f[i][j]+a[i+1]);
        }
        fo(i,1,n)if(f[n][i]<INF)ans=max(ans,i);
        printf("%d\n",ans);
    }

    return 0;
}