#include <stdio.h>
#include <stdlib.h>
#include <ctype.h>
typedef struct node{
    int val;
    struct node*prev,*next;
}node;
int is_integer_token(const char*s){
    if(!s|| *s=='\0') return 0;
    int i=0;
    if (s[0]=='-'||s[0]=='+'){
        if (s[1]=='\0') return 0;
        i=1;
    }
    for (;s[i];++i) if (!isdigit((unsigned char)s[i])) return 0;
    return 1;
}
node* append(node *tail,int v){
    node *n=malloc(sizeof(node));
    n->val=v;
    n->next=NULL;
    n->prev=tail;
    if (tail) tail->next=n;
    return n;
}
void free_list(node*head){
    node*cur=head;
    while(cur){
        node*t=cur;cur=cur->next;free(t);
    }
}
int main(){
    char tok[128];
    if (scanf("%127s",tok)!=1){
        printf("Invalid input");
        return 0;
    }
    if(!is_int_tok(tok)){
        printf("Invalid input");
        return 0;
    }
    int n=atoi(tok);
    if(n<0){
        printf("Invalid input");
        return 0;
    }
    node *head=NULL,*tail=NULL;
    int invalid=0;
    for(int i=0;i<n;i++){
        if (scanf("%127s",tok)!=1){
            invalid=1;break;
        }
        if (!is_int_tok(tok)){
            invalid=1;
        }
        else{
            int v=atoi(tok);
            if(!tail) head=tail=append(NULL,v);
            else tail=append(tail,v);
        }
    }
    if (scanf("%127s",tok)!=1){
        free_list(head);
        printf("Invalid input");
        return 0;
    }
    if(!is_int_tok(tok)||invalid){
        free_list(head);
        printf("Invalid input");
        return 0;
    }
    int target=atoi(tok);
    node *cur=head;
    int found=0;
    while(cur){
        if(cur->val==target){
            found=1;
            break;
        }
        cur=cur->next;
    }
    free_list(head);
    if (found) printf("Found");
    else printf("Not found");
    return 0
}