def funny_string(S):
    """A string is funny if

    S[i]-S[i-1] == R[i]-R[i-1]  for all i > 0

    where R is the reverse of S
    """
    S = S.lower()
    R = "".join(reversed(S))
    for i, s in enumerate(S[1:], 1):
        d1 = abs(ord(S[i - 1]) - ord(s))
        d2 = abs(ord(R[i - 1]) - ord(R[i]))
        if d2 != d1:
            return False
    return True