import java.io.*;
class TSECJ101 {
 
    public static int findBalancePoint(int[] arr) {
    int sum=0;
    for(int i=0, l=arr.length; i<l; i++){
      sum+=arr[i];
    }
    int lsum=0;
    int rsum=sum;
    for(int i=0, l=arr.length; i<l; i++){
      rsum=rsum-arr[i];
      if(lsum==rsum){
        return i;
      }
      lsum=lsum+arr[i];
    }
    return -1;
  }
    public static void main(String args[])throws IOException{
 
        InputStreamReader isr=new InputStreamReader(System.in);
        BufferedReader br=new BufferedReader(isr);
 
        int t=Integer.parseInt(br.readLine());
        for(int u=0; u<t; u++){
            int n=Integer.parseInt(br.readLine());
            int arr[]=new int[n];
            String line = br.readLine();
            String[] strs = line.trim().split(" ");
            for (int i = 0; i < n; i++) {
                arr[i] = Integer.parseInt(strs[i]);
            }
            System.out.println(findBalancePoint(arr));
        }
    }
}
 

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