#include<iostream>
#include<list>
using namespace std;
struct node{int z;node *prev;node *next;};
typedef node *pnode;
int main(){
	pnode head=NULL,tail,mid,el;
	int n,i,j,k=0;string w;
	cin>>n;
	for(i=0;i<n;i++){
		cin>>w;
		if(w=="add"){
			cin>>j;k++;
			el=new node;
			el->z=j;
			el->prev=NULL;
			el->next=NULL;
			if(head){
				el->prev=tail;
				tail->next=el;
				tail=el;
				if(k>2&&k%2==0)mid=mid->next;}
			else{head=el;tail=el;mid=el;}}
		else if(w=="take"){k--;
			el=tail->prev;
			el->next=NULL;
			delete(tail);
			tail=el;
			if(k>2&&k%2)mid=mid->prev;}
			else {
				tail->next=head;
				head=mid->next;
				mid->next=NULL;
				tail=mid;}}
			cout<<k<<endl;
			el=head;
			while(el){cout<<el->z<<' ';el=el->next;}
return 0;}