// editor1
#include<stdio.h>
#include<stdlib.h>
typedef struct node{
    int data;
    struct node *left;
    struct node *right;
    
}nd;
nd *root=NULL;
nd *create(int val){
    if(val==0){
        return NULL;
        
    }
    nd *newnode=(nd*)malloc(sizeof(nd));
    newnode->data=val;
    newnode->left=NULL;
    newnode->right=NULL;
    return newnode;
    
}
nd *insertBST(nd *root,int t){
    if(root==NULL){
return create(t);        
    }
     if(t<root->data){
         root->left=insertBST(root->left,t);
     }
     else{
         root->right=insertBST(root->right,t);
     }
     return root;
}
void postorder(root->left){
if(root==NULL){
    return ;
}
postorder(root->left);
postorder(root->right);
printf("%d",root->data);
return ;
}
int main(){
    int n;
    scanf("%d",&n);
    if(n<0){
        printf("Invalid input");
        return 0;
    }
    nd *root=NULL;
    for(int i=0;i<n;i++){
        int t;
        scanf("%d",&t);
        if(t<=n){
            printf("")
        }
    }
    
}