#include<bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef pair<int, int> PII;

const int MAXN = 2e3 + 10;
const int MM = 1e9 + 7;
const ll INF = 1ll << 60;

int n;
ll a[MAXN], b[MAXN], s[MAXN];
ll f[MAXN][MAXN];

void upd(ll &x, ll y) {
    x = min(x, y);
}

void solve(int casi){
    scanf("%d", &n);
    for (int i = 1; i <= n; i++) scanf("%lld", &a[i]);
    s[0] = 0;
    for (int i = 1; i <= n; i++) {
        scanf("%lld", &b[i]);
        s[i] = s[i - 1] + b[i];
    }
    for (int i = 0; i <= n; i++) {
        for (int j = 0; j <= n; j++) {
            f[i][j] = INF;
        }
    }
    f[0][0] = 0;
    for (int i = 1; i <= n; i++) {
        for (int j = 0; j < i; j++) {
            // gugugu i
            upd(f[i][j + 1], f[i - 1][j]);
            // gan i
            if (f[i - 1][j] + a[i] <= s[i])
                upd(f[i][j], f[i - 1][j] + a[i]);
        }
    }
    int ans = 0;
    for (int j = 0; j <= n; j++) {
        if (f[n][j] < INF) {
            ans = max(ans, n - j);
        }
    }
    printf("%d\n", ans);
}

int main(){
    int T = 1;
    scanf("%d", &T);
    for (int i = 1; i <= T; i++)
        solve(i);
    return 0;
}