#include<bits/stdc++.h>
#define debug(x) cerr<<#x<<" = "<<x
#define sp <<"  "
#define el <<endl
#define fgx cerr<<"-----------------------------------"<<endl
#define LL long long
#define DB double
#define pb push_back
using namespace std;
inline LL read(){
    LL nm=0; bool fh=1; char cw=getchar();
    for(;!isdigit(cw);cw=getchar()) fh^=(cw=='-');
    for(;isdigit(cw);cw=getchar()) nm=nm*10+(cw-'0');
    return fh?nm:-nm;
}
#define M 2020
#define INF 10000000000000000ll
LL A[M],B[M],pre[M],F[M][M];
int n;
inline int solve(){
    n=read();
    for(int i=1;i<=n;i++) A[i]=read();
    for(int i=1;i<=n;i++) B[i]=read(),pre[i]=pre[i-1]+B[i];
    for(int i=0;i<=n;i++) for(int j=1;j<=i;j++) F[i][j]=INF;
    for(int i=1;i<=n;i++) for(int bef=0;bef<i;bef++){
        F[i][bef]=min(F[i][bef],F[i-1][bef]);
        if(F[i-1][bef]+A[i]<=pre[i]) F[i][bef+1]=min(F[i][bef+1],F[i-1][bef]+A[i]);
        
    }
    for(int i=n;i>=0;--i) if(F[n][i]<=pre[n]) return i; return -1;
}
int main(){
    for(int Cas=read();Cas;--Cas) printf("%d\n",solve());
    return 0;
}