#include<map>
#include<set>
#include<queue>
#include<stack>
#include<cmath>
#include<cstdio>
#include<vector>
#include<string>
#include<cstring>
#include<ctype.h>
#include<iostream>
#include<algorithm>
using namespace std;
#define INF (1 << 30)
#define LINF (1LL << 60)
#define PI acos(-1.0)
#define mem(a, b) memset(a, b, sizeof(a))
#define rep(i, a, n) for (int i = a; i < n; i++)
#define per(i, a, n) for (int i = n - 1; i >= a; i--)
#define eps 1e-8
#define debug puts("===============")
#define pb push_back
#define mkp make_pair
#define all(x) (x).begin(),(x).end()
#define fi first
#define se second
#define SZ(x) ((int)(x).size())
#define POSIN(x,y) (0 <= (x) && (x) < r && 0 <= (y) && (y) < c)
typedef long long ll;
typedef unsigned long long ULL;
int main()
{
  int test;
  ll a[2005],b[2005],sumb[2005];
  scanf("%d", &test);
  rep(iii, 0, test) {
    int n;
    ll dp[2005];
    mem(dp, -1);
    scanf("%d", &n);
    rep(i, 0, n){
      scanf("%lld", &a[i]);
    }
    rep(i, 0, n){
      scanf("%lld", &b[i]);
      sumb[i] = b[i];
      if (i != 0) sumb[i] += sumb[i-1];
    }
    dp[0] = 0;
    int ans = 0;
    rep(i, 0, n) {
      for (int j = i+1; j > 0; j--) {
        if (dp[j-1] == -1) continue;
        if (dp[j-1] + a[i] <= sumb[i]) {
          if (dp[j] == -1) dp[j] = dp[j-1] + a[i];
          dp[j] = min(dp[j], dp[j-1] + a[i]);
          ans = max(ans, j);
        }
      }
    }
    printf("%d\n", ans);
  }
}