#include <iostream>
#include <cstdio>
#include <vector> 
#include <cstring>
#include <algorithm>
using namespace std;

const int N = 2e3 + 100;
const int INF = 0x3f3f3f3f;
long long a[N], b[N], t[N];
long long dp[N][N];
int main(){
    int T;
    cin >> T;

    while (T --){
        int n;
        cin >> n;
        for (int i = 1; i <= n; i ++) cin >> a[i];
        b[0] = 0;
        for (int i = 1; i <= n; i ++){
            cin >> b[i];
            b[i] += b[i - 1];
        }
        long long ma = 1e18;
        memset(dp, 0x3f, sizeof(dp));
//        cout << dp[0][0] << endl;
        dp[0][0] = 0;
        for (int i = 1; i <= n; i ++){
            dp[i][0] = 0;
            for (int j = 1; j <= i; j ++){
                dp[i][j] = dp[i - 1][j];
                if (dp[i - 1][j - 1] + a[i] <= b[i]){
                    dp[i][j] = min(dp[i][j], dp[i - 1][j - 1] + a[i]);
                }
            }
        }
        int ans;
        for (int i = n; i >= 0; i --) if (dp[n][i] <= ma){
            ans = i;
            break;
        }
        cout << ans << endl;
    }
}