def convertLUtoUN(s):
    """Capitalize a string."""
    r = ''
    i = 0
    while i < len(s):
        if i == 0:
            r += s[i].upper()
            i += 1
        elif s[i] == '_' and i < len(s) - 1:
            r += s[i + 1].upper()
            i += 2
        else:
            r += s[i]
            i += 1
    return r
