#include<bits/stdc++.h>
#define ll long long
using namespace std;
const int MAXN=2000+5;
const int MOD=(1<<10)-1;
int n,T;
ll a[MAXN],b[MAXN];
ll dp[MAXN];
void solve()
{
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%d",a+i);
    for(int i=1;i<=n;i++)
        scanf("%d",b+i),b[i]+=b[i-1];
    for(int i=0;i<=n+1;i++)
        dp[i]=-1;
    dp[0]=1ll<<60;
    for(int i=n+1;i>1;i--)
    for(int j=n;j>=0;j--)
    {
        ll nd=min(dp[j]-a[i-1],b[i-1]-a[i-1]);
        if(nd<0) continue;
        dp[j+1]=max(nd,dp[j+1]);
    }
    for(int i=n;i>=0;i--)
    if(dp[i]!=-1)
    {
        printf("%d\n",i);
        break;
    }
}
int main()
{ 
    scanf("%d",&T);
    while(T--)
        solve();
    return 0;
}