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; } } } } }