def string_without_currency(s):
    """
    Return a string without leading or trailing currency symbols.

    Strip leading and trailing currency symbols, and currency symbols
    at position 1 if first character is + or -
    """
    currency_symbols = '$€£¥¢'
    s = s.strip(currency_symbols)
    if len(s) > 2 and s[0] in '+-' and s[1] in currency_symbols:
        s = s[0] + s[2:]
    return s