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

int isMinHeap(int arr[], int len)
{
    for (int i = 0; i <= (len - 2) / 2; i++)
    {
        int l = 2 * i + 1;
        int r = 2 * i + 2;
        if ((l < len && arr[i] > arr[l]) || (r < len && arr[i] > arr[r]))
        {
            return 0;
        }
    }
    return 1;
}

void printPreorder(int arr[], int len, int index, int level)
{
    if (index >= len) 
    {
        return;
    }

    for (int i = 0; i < level; i++) 
    {
        printf(" ");
    }
    printf("%d\n", arr[index]);

    printPreorder(arr, len, 2 * index + 1, level + 1);
    printPreorder(arr, len, 2 * index + 2, level + 1);
}

int main()
{
    char input[1000];
    fgets(input, sizeof(input), stdin);

    int kopa[100];
    int c = 0;
    char *token = strtok(input, " ");
    while (token != NULL)
    {
        kopa[c++] = atoi(token);
        token = strtok(NULL, " ");
    }

    if (isMinHeap(kopa, c))
    {
        printf("Je to taka kopa:\n");
        printPreorder(kopa, c, 0, 0);
    }
    else
    {
        printf("Nie je kopa.\n");
    }

    return 0;
}