Parking

#include <iostream>
#include <map>
#include <set>
#include <vector>
using namespace std;
int main() {
    unsigned int m;
    cin >> m;
    map<unsigned int, unsigned int> parking;
    set<unsigned int> free;
    for (unsigned int i = 0; i < m; i++) {
        free.insert(i + 1);
    }
    char t_c;
    unsigned int t_v;
    for (unsigned int i = 0; i < m; i++) {
        cin >> t_c >> t_v;
        if (t_c == '+') {
            unsigned int place = *free.begin();
            parking.insert({t_v, place});
            cout << place << "\n";
            free.erase(place);
        }
        else {
            unsigned int place = parking[t_v];
            free.insert(place);
            parking.erase(t_v);
        }
    }
    return 0;
}