#include <bits/stdc++.h>   using namespace std;   using vi = vector<int>;   int main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     int t = 1;     cin >> t;     vi v(t);     for (int i = 0; i < t; i++) {       cin >> v[i];     }     int m = t;     priority_queue<int> qi;     for (int i = 0; i < t; i++) {       if (v[i] == m) {         m--;         cout << v[i] <<    ;         while (!qi.empty() && (qi.top() == m)) {           m--;           cout << qi.top() <<    ;           qi.pop();         }       } else         qi.push(v[i]);       cout <<   n ;     }     cerr <<   ntime taken :   << (float)clock() / CLOCKS_PER_SEC <<   secs           << endl;     return 0;   }   