#include<iostream>
#include<stdio.h>
#include<math.h>
#include<string>
#include<string.h>
#include<algorithm>
#include<vector>
using namespace std;
#define ll long long 
const int maxn = 2010;
const ll INF = 1e15;
int n;
ll a[maxn];
ll b[maxn];
ll dp[maxn][maxn];
void init()
{
    for(int i=0;i<=n;i++)
        for(int j=0;j<=n;j++)
            dp[i][j]=-INF;
    dp[0][0]=0;
}
int main()
{
    int t; scanf("%d",&t);
    while(t--)
    {
        scanf("%d",&n);
        for(int i=1;i<=n;i++) scanf("%lld",&a[i]);
        for(int i=1;i<=n;i++) scanf("%lld",&b[i]);
        init();
        for(int i=1;i<=n;i++)
            for(int j=0;j<=i;j++)
            {
                if(j&&(a[i]-dp[i-1][j-1]<=b[i]))
                dp[i][j]=max(dp[i][j],b[i]-(a[i]-dp[i-1][j-1]));
                dp[i][j]=max(dp[i][j],dp[i-1][j]+b[i]);
            }
        int ans=0;
        for(int i=1;i<=n;i++) 
        if(dp[n][i]>=0) ans=i;
        printf("%d\n",ans);
     }
    return 0;
}