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

#define N -1000000000

struct Node {
    int n;
    struct Node *next;
};

struct Node *createNode(int n) {
    struct Node *elem = (struct Node *) malloc(sizeof(struct Node));
    elem->n = n;
    elem->next = NULL;
    return elem;
};

int remove1(int n, struct Node *head) {
    struct Node *prev = head;
    prev = head;
    if (head->n == n) {
        head = head->next;
        prev->next = NULL;
        return 1;
    }
    head = head->next;
    while (head != NULL) {

        if(head->n == n){
            prev->next = prev->next->next;
            return 1;
        }
        prev = head;
        head = head->next;
    }
    return -1;
}

int main() {
    char end = ' ';
    int n;
    struct Node *head;
    struct Node *elem;
    struct Node *prev;
    int c;
    for (int i = 0; i < 11; i++) {
        scanf("%d%c", &n, &end);
        elem = createNode(n);
        if (i == 0) {
            c = n;
            continue;
        }
        if (i == 1) {
            head = elem;
            prev = head;
            continue;
        }
        prev->next = elem;
        prev = elem;
        if (end == '\n')
            break;
    }
    printf("%d", remove1(c, head));

}