func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int n;     cin >> n;     vector<int> a(n);     for (int i = 0; i < n; ++i) cin >> a[i];     map<int, int> used;     int ans = 0;     for (int i = n - 1; i >= 0; --i) {       if (used[a[i]] == 0) {         used[a[i]] = i;         ans = a[i];       }     }     cout << ans;     return 0;   }   