#include <stdio.h>
#include <stdlib.h>
#define MAX 20

struct node {
    int data;
    struct node* left;
    struct node* right;
};
void preorderTraversal(struct node* root) {
    if (root == NULL) return;
    printf("%d", root->data);
    preorderTraversal(root->left);
    preorderTraversal(root->right);
}
int main() {
//int l = i * 2 + 1;
//int r = i * 2 + 2;
struct node* root;
    int i,n;
    int *a = calloc(MAX, sizeof(int));
    for (i = 0; i < MAX; i++) {
        scanf("%d", root->data);
        if(a[i]!=0){
            n++;
        }
    }

    printf("Je to taka kopa:\n");
    /*for (i = 0; i < n; i++) {
        printf("%d\n", a[i]);
        if(a[i+1]!=0){
        }
    }*/
    preorderTraversal(root);

return 0;
}