#include <bits/stdc++.h>

using namespace std;

#define N 200007
#define INF 0x3f3f3f3f
#define LL long long

LL a[N], b[N], f[N];

int main()
{
    int T;
    scanf("%d", &T);
    b[0] = 0;
    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(f, -1, sizeof(f));
        f[0] = 0;
        for (int i = 1; i <= n; i++)
        {
            for (int j = i; j > 0; j--)
            {
                if (f[j - 1] == -1LL) continue;
                if (f[j - 1] + a[i] <= b[i])
                {
                    if (f[j] == -1) f[j] = f[j - 1] + a[i];
                    else f[j] = min(f[j], f[j - 1] + a[i]);
                }
            }
        }
        int ans = 0;
        for (int i = 1; i <= n; i++) if (f[i] != -1) ans = i;
        printf("%d\n", ans);
    }
    return 0;
}