#include <stdio.h>
#include <stdlib.h>

struct node {
  int info;
  struct node *next;
};

typedef struct node*  Node;

void list_insert( int n, Node *l);
void list_print(Node l);
void list_delete(int n, Node *l);
int isIn(int n, Node l);
int list_count(Node l);
void list_print_rec(Node l);
void list_destroy(Node l);

int main (void) {
    Node head;
    char op;
    int n;
    int count = 0;

while ((op = getchar()) != 'f') {
    /*scanf(" %c", &op);
    if (op == 'f')
        break;
    */

    switch (op) {
        case '+':
            scanf("%d",&n);
            list_insert(n,&head);
            list_print(head);
            printf("\n");
            break;
        case '-':
            scanf("%d",&n);
            list_delete(n, &head);
            list_print(head);
            printf("\n");
            break;
        case '?':
            scanf("%d", &n);
            if (isIn(n, head)) {
                printf("%d appartiene all'insieme\n",n);
            } else
                printf("%d non appartiene all'insieme\n",n);
            break;
        case 'p':
            list_print(head);
            printf("\n");
            break;
        case 'c':
            printf("%d\n",list_count(head));
            break;
        case 'o':
            list_print_rec(head);
            break;
    }
}

}

void list_insert( int n, Node *l){
    Node curr = *l;

    while (curr != NULL) {
        if (curr -> info == n)
            return;
        curr = curr -> next;
    }

    Node new = malloc(sizeof(struct node));
    new -> info = n;
    new -> next = *l;
    *l = new;
}

void list_delete( int n, Node *l){
    Node curr, prev;

    for ( curr = *l, prev = NULL; curr != NULL; prev = curr, curr = curr -> next )
        if (curr -> info == n )
            break;

    if (curr == NULL)
        return;
    if (prev == NULL)
        *l = (*l)->next;
    else
        prev -> next = curr -> next;

    free(curr);
}

void list_print(Node l) {
    struct node *curr = l;
    while (curr != NULL) {
        printf("%d ", curr -> info);
        curr = curr -> next;
    }
}

int isIn(int n, Node l) {
    Node curr = l;
    while (curr != NULL) {
        if (curr -> info == n)
            break;
        curr = curr -> next;
    }

    if (curr == NULL)
        return 0;
        else
            return 1;
}

int list_count(Node l) {
    int count = 0;
    Node curr = l;

    while (curr != NULL) {
        count++;
        curr = curr -> next;
    }
    return count;
}

void list_print_rec(struct node *l) {
 if (l!= NULL) {
    list_print_rec(l -> next);
    printf("%d ", l -> info);
  }
}

void list_destroy(struct node *l) {
    struct node *curr = l;
    struct node *prev = NULL;

    while (curr != NULL){
      prev = curr;
      curr = curr -> next;
      free(prev);
    }
}