What is the worst-case time complexity of this function?

• Try to find the tightest upper bound you can.
• Try to simplify as much as you can.
• Even if your answer isn't the tightest upper bound/the most simplified, still write your attempt - there are partial marks.
• Provide some reasoning for your answer (no explanation, no marks), and don't forget to define the variables you use.

def func(n):
    counter = 0
    i = 1
    while i <= n:
        for j in range(i):
            counter += 1
        i *= 2
    
    return counter