def is_min_heap(arr):
    n = len(arr)
    for i in range(n):
        l = 2 * i + 1 
        r = 2 * i + 2  
        if l < n and arr[i] > arr[l]:
            return False
        if r < n and arr[i] > arr[r]:
            return False
    return True

def preorder(arr, index, level):
    if index >= len(arr):
        return
    print(' ' * level + str(arr[index]))
    l = 2 * index + 1
    r = 2 * index + 2
    if l < len(arr):
        preorder(arr, l, level + 1)
    if r < len(arr):
        preorder(arr, r, level + 1)

def main():
    # Načítanie vstupu
    arr = list(map(int, input().split()))
    
    if is_min_heap(arr):
        print("Je to taka kopa:")
        preorder(arr, 0, 0)
    else:
        print("Nie je kopa.")


if __name__ == "__main__":
    main()