#include<stdio.h>
#include<stdlib.h>
typedef struct node
{
    int data;
    struct *right,*left;
}Node;
Node *left,*right;
Node *createNode(int num){
    Node*newNode=(Node*)malloc(sizeof(Node));
    newNode->data=num;
    newNode->left=NULL;
    newNode->right=NULL;
    return newNode;
}
int main(){
    int i,N,value;
    scanf("%d",&N);
    if(scanf("%d",&N)!=1){
        printf("Invalid input");
        return 0;
    }
    if(N<=0){
        printf("Invalid input");
        return 0;
    }
    Node*root=NULL;
    for(i=0;i<=value;i++){
        if(scanf("%d",&value));
        {
            printf("Invalid input");
            return 0;
        }
    
    if(value<0){
        printf("Invalid input");
        return 0;
    }
    
    Node*temp=createNode(value);
    }
    printf("%d",value);
    return 0;
}