def symbol_converted(symbol):
    """
    Input: symbol in the form '0005.HK' (from Alpha Vantange data)
    Output: symbol in the form '5' (for TWS)
    """
    slice_index = 0
    for i in range(0,4):
        if symbol[i]=='0':
            slice_index = i+1
        else:
            break
    return symbol[slice_index:-3]