#include <stdio.h>
#include <string.h>
#include <algorithm>
#define MN 2000
typedef long long LL;

int n,a[MN+5],b[MN+5];

LL f[MN+5];

LL preb[MN+5];

void solve(){
    memset(f,0x7f,sizeof(f));
    scanf("%d",&n);
    for(int i=1;i<=n;i++)
        scanf("%d",&a[i]);
    for(int i=1;i<=n;i++){
        scanf("%d",&b[i]);
        preb[i] = preb[i-1]+b[i];
    }
    f[0] = 0;
    for(int i=1;i<=n;i++){
        for(int j=i;j>=1;j--){
            if(preb[i]>=f[j-1]+a[i])
                f[j] = std::min(f[j],f[j-1]+a[i]);
        }
    }
    for(int i=n;i>=1;i--)
        if(f[i] != 0x7f7f7f7f7f7f7f7f){
            printf("%d\n",i);
            break;
        }
}

int main(){
    int T; scanf("%d",&T);
    while(T--) solve();
}