# include <bits/stdc++.h>
using namespace std;
namespace Base{
    # define mr make_pair
    typedef long long ll;
    typedef double db;
    const int inf = 0x3f3f3f3f, INF = 0x7fffffff;
    const ll  infll = 0x3f3f3f3f3f3f3f3fll, INFll = 0x7fffffffffffffffll;
    template<typename T> void read(T &x){
        x = 0; int fh = 1; double num = 1.0; char ch = getchar();
        while (!isdigit(ch)){ if (ch == '-') fh = -1; ch = getchar(); }
        while (isdigit(ch)){ x = x * 10 + ch - '0'; ch = getchar(); }
        if (ch == '.'){
            ch = getchar();
            while (isdigit(ch)){num /= 10; x = x + num * (ch - '0'); ch = getchar();}
        }
        x = x * fh;
    }
    template<typename T> void chmax(T &x, T y){x = x < y ? y : x;}
    template<typename T> void chmin(T &x, T y){x = x > y ? y : x;}
}
using namespace Base;

const int N = 2020;
ll a[N], b[N], f[N][N];
int n;
int main(){
    int T; read(T);
    while (T--){
        read(n);
        for (int i = 1; i <= n; i++) read(a[i]);
        for (int i = 1; i <= n; i++){
            read(b[i]); b[i] = b[i - 1] + b[i];
        }
        for (int i = 0; i <= n; i++)
            for (int j = 1; j <= n; j++)
                f[i][j] = infll;
        int ans = 0;
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= i; j++){
                f[i][j] = f[i - 1][j];
                if (f[i - 1][j - 1] + a[i] <= b[i])
                    f[i][j] = min(f[i][j], f[i - 1][j - 1] + a[i]);
                if (f[i][j] != infll) ans = max(ans, j);
            }
        cout << ans << endl;
    }
    return 0;
}