If n=4
Output

A
AB
BCC
CDDD

If n=5
Output

A
AB
BCC
CDDD
DEEEE

def print_pyramid(N):
    # Iterate over each row from 1 to N
    for i in range(N):
        # Calculate the starting character for each row
        start_char = chr(ord('A') + i)

        # Calculate the number of times to repeat the starting character
        repeat_count = i + 1

        # Generate the current row
        row = ''.join([chr(ord(start_char) + j) for j in range(repeat_count)])

        # Print the current row
        print(row)

Example usage:

N = 4

print_pyramid(N)