def fix_spaces(text):
    """
    Given a string text, replace all spaces in it with underscores, 
    and if a string has more than 2 consecutive spaces, 
    then replace all consecutive spaces with - 
    
    fix_spaces("Example") == "Example"
    fix_spaces("Example 1") == "Example_1"
    fix_spaces(" Example 2") == "_Example_2"
    fix_spaces(" Example   3") == "_Example-3"
    """
    new_text = ""
    i = 0
    start, end = 0, 0
    while i < len(text):
        if text[i] == " ":
            end += 1
        else:
            if end - start > 2:
                new_text += "-"+text[i]
            elif end - start > 0:
                new_text += "_"*(end - start)+text[i]
            else:
                new_text += text[i]
            start, end = i+1, i+1
        i+=1
    if end - start > 2:
        new_text += "-"
    elif end - start > 0:
        new_text += "_"
    return new_text