#include <bits/stdc++.h>
using namespace std;
int n, t;
long long a[2010], b[2010];
long long d[2010][2010];
int main() {
    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), b[i] += b[i - 1];
        memset(d, 0x3f, sizeof d);
        d[0][0] = 0;
        for (int i = 1; i <= n; i++) {
            for (int j = 0; j <= n; j++) {
                d[i][j] = min(d[i][j], d[i - 1][j]);
                if (d[i - 1][j] + a[i] <= b[i]) d[i][j + 1] = min(d[i][j + 1], d[i - 1][j] + a[i]);
            }
        }
        int ans = 0;
        for (int i = 1; i <= n; i++)
            for (int j = 0; j <= n; j++) if (d[i][j] <= 1e14) ans = max(ans, j);
        printf("%d\n", ans);
    }
}