from collections import Counter , deque
for s in [*open(0)][2::2]:
s = list(map(int,s.split()))
x = min(s)
arr = Counter(s)
lst = deque()
for key , value in arr.items():
if value == 1:
lst.append(key)
lst = sorted(lst)
if lst:
x = lst[0]
print(s.index(x)+1)
else:
print(-1)#include <iostream>
#include <algorithm>
#include <cmath>
#include <vector>
#include <stack>
#include <cstring>
#include <queue>
#include <set>
#include <map>
#include <cstdio>
#define ll long long
#define pcl std::pair<char, long long>
#define IOS ios::sync_with_stdio(0), std::cin.tie(0), std::cout.tie(0)
#define endl "\n"
const int maxn=1e6;
int t,n, m;
void solve()
{
std::cin>>n;
std::map<int,int>num,pos;
for(int i=1;i<=n;i++){
int x;
std::cin>>x;
num[x]++;
pos[x]=i;
}
int ans=-1;
for(auto it:num){
if(it.second==1){
ans=pos[it.first];
break;
}
}
std::cout<<ans<<endl;
}
int main(){
std::IOS;
std::cin>>t;
while(t--)
{
solve();
}
return 0;
}
199A - Hexadecimal's theorem | 519C - A and B and Team Training |
631A - Interview | 961B - Lecture Sleep |
522A - Reposts | 1166D - Cute Sequences |
1176A - Divide it | 1527A - And Then There Were K |
1618E - Singers' Tour | 1560B - Who's Opposite |
182B - Vasya's Calendar | 934A - A Compatible Pair |
1618F - Reverse | 1684C - Column Swapping |
57C - Array | 1713D - Tournament Countdown |
33A - What is for dinner | 810A - Straight A |
1433C - Dominant Piranha | 633A - Ebony and Ivory |
1196A - Three Piles of Candies | 299A - Ksusha and Array |
448B - Suffix Structures | 1092B - Teams Forming |
1166C - A Tale of Two Lands | 544B - Sea and Islands |
152B - Steps | 1174D - Ehab and the Expected XOR Problem |
1511A - Review Site | 1316A - Grade Allocation |