#include<bits/stdc++.h>
using namespace std;
long long t,n,a[1000010],ans,l,r,mid;
long long sum1[1000010],sum2[1000010];
long long read(){
	char ch=getchar();
	long long sgn=1,x=0;
	while(ch<'0'||ch>'9'){
		if(ch=='-'){
			sgn=-1;
		}
		ch=getchar();
	}
	while(ch>='0'&&ch<='9'){
		x=(x<<3)+(x<<1)+(ch&15);
		ch=getchar();
	}
	return x*sgn;
}
void write(long long n,bool p){
	if(n<0){
		putchar('-');
		n=-n;
	}
	if(n==0){
		if(p==true){
			putchar('0');
		}
		return;
	}
	write(n/10,0);
	putchar(n%10+'0');
}
int main(){
	t=read();
	while(t--){
		n=read();
		ans=0;
		for(int i=1;i<=n;i++){
			a[i]=read();
		}
		for(int i=1;i<=n;i++){
			sum1[i]=sum1[i-1]+a[i];
		}
		for(int i=n;i>=1;i--){
			sum2[i]=sum2[i+1]+a[i];
		}
		for(int i=1;i<=n;i++){
			l=i+1;
			r=n;
			while(l<=r){
				mid=(l+r)/2;
				if(sum1[i]==sum2[mid]){
					ans=max(ans,i+n-mid+1);
//					cout<<i<<" "<<mid<<endl;
					r=mid-1;
				}
				if(sum1[i]<sum2[mid]){
					l=mid+1;
				}
				if(sum1[i]>sum2[mid]){
					r=mid-1;
				}
			}
		}
		printf("%lld\n",ans);
//		cout<<"-----------------";
	}
	return 0;
}