#include <bits/stdc++.h>
using namespace std;

const long long INF = 0x3f3f3f3f3f3f3f3f;

long long dp[2010], ndp[2010];
long long a[2010], b[2010];

int main () {
    int T; scanf("%d", &T);
    while (T--) {
        int n; 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]);
            b[i] += b[i - 1];
        }
        memset(dp, 0x3f, sizeof(dp));
        dp[0] = 0;
        for (int i = 1; i <= n; i++) {
            memset(ndp, 0x3f, sizeof(ndp));
            for (int j = 0; j <= n; j++) {
                ndp[j] = min(ndp[j], dp[j]);
                if (dp[j] + a[i] <= b[i]) {
                    ndp[j + 1] = min(ndp[j + 1], dp[j] + a[i]);
                }
            }
            swap(dp, ndp);
        }
        for (int i = n; i >= 0; i--) {
            if (dp[i] != INF) {
                printf("%d\n", i);
                break;
            }
        }
    }
    return 0;
}