#include <bits/stdc++.h>

using namespace std;

const long long inf = 1000000000000000001;

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int T;
    cin >> T;

    while(T--) {
        int n;
        cin >> n;

        vector<int> a(n);
        for(int i = 0; i < n; ++i) {
            cin >> a[i];
        }

        vector<int> b(n);
        for(int i = 0; i < n; ++i) {
            cin >> b[i];
        }

        vector<long long> pre(n);
        pre[0] = b[0];
        for(int i = 0; i + 1 < n; ++i) {
            pre[i + 1] = pre[i] + b[i + 1];
        }

        vector<vector<long long> > dp(n + 1, vector<long long> (n + 1, inf));
        dp[0][0] = 0;

        for(int i = 0; i < n; ++i) {
            for(int j = 0; j <= i; ++j) {
                dp[i + 1][j] = min(dp[i + 1][j], dp[i][j]);
                if(dp[i][j] < inf && pre[i] >= dp[i][j] + a[i]) {
                    dp[i + 1][j + 1] = min(dp[i + 1][j + 1], dp[i][j] + a[i]);
                } 
            }
        }

        for(int i = n; i >= 0; --i) {
            if(dp[n][i] < inf) {
                cout << i << '\n';
                break;
            }
        }
    }

    return 0;
}