CODEFORCES SPY DETECTED ROUND 713

 import java.util.*;

public class CodeForcesSpyDetected{

public static void main(String arg[]){

Scanner sc=new Scanner(System.in);

int t=sc.nextInt();

ArrayList <Integer> aa=new ArrayList<Integer>(); 

while(t -->0){

int n=sc.nextInt();

int arr2[]=new int[n];

for(int i=0;i<n;i++){

arr2[i]=sc.nextInt();

}

for(int i=0;i<n;i++){

aa.add(arr2[i]);

}

for(int i=0;i<aa.size();i++){

//System.out.println(Collections.frequency(aa,aa.get(i)));

if(Collections.frequency(aa,aa.get(i))==1){

System.out.println((i+1));

aa.clear();

break;

}

}

}

}

}