#include <bits/stdc++.h>
using namespace std;
#define int long long
void solve(){
int n;
cin>>n;
vector<int> v(n);
for(int i=0;i<n;i++)cin>>v[i];
map<int,int> mp;
int sum=0;
for(int i=0;i<n;i++){
sum+=v[i];
mp[sum]=i;
}
sum=0;
int j=n-1;
int i=-1;
int ans=0;
while(j>i){
sum+=v[j];
if(mp.find(sum)!=mp.end() && j>mp[sum]){
i=mp[sum];
ans=max(ans,i+1+n-j);
}
j--;
}
cout<<ans<<endl;
}
signed main() {
// your code goes here
int t;
cin>>t;
while(t--){
solve();
}
return 0;
}
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