// editor5
#include<stdio.h>
#include<stdlib.h>
typedef struct TreeNode{
    int data;
    struct TreeNode *left;
    struct TreeNode *right;
}Node;
Node*root=NULL;
Node *create(int num){
    Node *newnode=(Node*)malloc(sizeof(Node));
    newnode->data=num;
    newnode->left=newnode->right=NULL;
    return newnode;
}
Node *insertBST(Node*root,int num){
    if(root==NULL){
        return create(num);
    }
    if(num <root->data){
        root->left=insertBST(root->left,num);
    }
    else{
        root->right=insertBST(root->right,num);
    }
    return root;
}

int countNodes(Node*root){
   while(root!=NULL){
       root=root->left;
       if(root->left==NULL){
           printf("%d",root->);
           break ;
       }
   }
}
int main(){
    int size,num,i;
    Node*root=NULL;
   scanf("%d",&size);
    if(size<=0){
        printf("Invalid input");
        return 0;
    }
    for(int i=0;i<size;i++){
        if(!scanf("%d",&num)){
            printf("Invalid input");
            return 0;
        }
        
        root=insertBST(root,num);
    }
  
   countNodes(root);
    return 0;
}