// UUID: 69d4e939-8081-4f8b-96a8-843ec017d9b3
#include <bits/stdc++.h>
using namespace std;
int main() {
int n;
cin>>n;
vector<int> input(n);
set<int> different_nums;
for (int& i:input){
cin>>i;
different_nums.insert(i);
}
set<int> was;
for (int i=n-1; i>=0; i--){
if (!was.contains(input[i])){
was.insert(i);
if (was.size()==different_nums.size()){
cout<<i+1;
return 0;
}
}
}
}
/*
---------------------------------------------------
Memorylimit reached:
vector<bool> was(1e9, false)
cin >> vector<int>
visszafelé végigmenni, menteni egy választ (pl. x)
for i:
ha még nem volt, akkor x--, was[]=true
cout << x
*/open /var/local/lib/isolate/420/box/a.out: no such file or directory
main.cpp: In function 'int main()':
main.cpp:17:26: error: 'class std::set<int>' has no member named 'contains'
17 | if (!was.contains(input[i])){
| ^~~~~~~~