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

typedef struct node{
    int data;
    struct node *next;
    
}Node;

Node *head= NULL, *tail;
void creation(int num){
    Node *newnode =(Node*) malloc(1 *sizeof(Node));
    newnode -> data = num;
    newnode ->next = NULL;
    if(head==NULL){
        head = newnode;
        tail = newnode;
        
    }
    else{
        tail -> next = newnode;
        newnode = tail;
        
    }
    
}

void display(){
     Node *itr;
     
}
int main(){
    int size,num,itr;
    scanf("%d",&size);
    for(itr=0;itr<size;Itr++){
        if(!scanf("%d",num)){
            printf("Invalid input");
            return 0;
            
        }
    }
}