func_code_string: #include <bits/stdc++.h>   using namespace std;   using li = long long;   using ld = long double;   void solve(bool);   int main() {     ios_base::sync_with_stdio(false);     cin.tie(nullptr);     cout << fixed << setprecision(20);     solve(true);     return 0;   }   const int maxn = (int)1e5 + 5;   int n, a[maxn];   map<int, int> m;   void solve(bool __attribute__((unused)) read) {     cin >> n;     for (int i = 0; i < n; ++i) {       cin >> a[i];       if (a[i] > 0 && !m.count(a[i] - 1)) {         cout << i + 1 <<   n ;         return;       }       m[a[i]] = 1;     }     cout << -1 <<   n ;     return;   }   