#include<bits/stdc++.h>

using namespace std;
#define ll long long

const int N = 2005;
int T, n;
ll a[N], b[N], f[N][N];
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(f, 0x3f, sizeof f), f[0][0]=0;
        for(int i=1; i<=n; ++i) for(int j=0; j<=i; ++j){
            f[i][j]=f[i-1][j];
            if(j>0 && f[i-1][j-1]+a[i]<=b[i]) f[i][j]=min(f[i][j], f[i-1][j-1]+a[i]);
        }
        for(int i=n; ~i; --i) if(f[n][i]<1e15){
            printf("%d\n", i);
            break;
        }
    }
    return 0;
}