// https://omegaup.com/arena/problem/Dobles-colas
#include <deque>
#include <iostream>
#include <string>

int main( ) {
   int n;
   std::cin >> n;

   std::deque<int> dc;
   for (int i = 0; i < n; ++i) {
      std::string s;
      std::cin >> s;

      if (s == "AGREGA_IZQ") {
         int v;
         std::cin >> v;
         dc.push_front(v);
      } else if (s == "AGREGA_DER") {
         int v;
         std::cin >> v;
         dc.push_back(v);
      } else if (s == "QUITA_IZQ") {
         dc.pop_front( );
      } else if (s == "QUITA_DER") {
         dc.pop_back( );
      } else if (s == "ROTA_IZQ") {
         dc.push_back(dc.front( ));
         dc.pop_front( );
      } else if (s == "ROTA_DER") {
         dc.push_front(dc.back( ));
         dc.pop_back( );
      }
   }

   for (int i = 0; i < dc.size( ); ++i) {
      std::cout << dc[i] << " ";
   }
}