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

typedef struct node{
    int data;
    struct node *right,*left;
}node;
node *root=NULL;

node* create(int num){
    node *newnode=(node*)malloc(1*sizeof(node));
    newnode->data=num;
    newnode->right=NULL;
    newnode->left=NULL;
    return newnode;
}

node *ins(node *root,int num){
    if(root==NULL){
        return create(num);
    }    
    if(num<root->left){
        root->left=ins(root->left,num);
    }
    else if(num>root->right){
        root->right=ins(root->right,num);
    }
    return root;
}

int main(){
    int s,n,i;
    scanf("%d",&s);
    if(s<0){
        printf("Invalid input");
        return
    }
    for(i=0;i<s;i++){
        scanf("%d",&n);
        root=ins(root,n);
    }
    printf("%d",s);
    return 0;
}