def largest_odd_element(arr):
largest_odd = None
for i in range(len(arr)):
if i % 2 != 0 and (largest_odd is None or arr[i] > largest_odd):
largest_odd = arr[i]
return largest_odd

arr = [2, 5, 7, 4, 9, 3, 6]
result = largest_odd_element(arr)
print("Наибольший элемент с нечетным порядковым номером:", result)