<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:

def restore_punctuation(original,modified):
    ''' If punctuation was accidently removed, use this function to restore it.
        requires the orignial string with punctuation. '''
    ret = ''
    count = 0
    try:
        for c in original:
            if c.isalpha(): 
                ret+=modified[count]
                count+=1
            else: ret+=c
    except IndexError:
        print('restore_punctuation: strings must have same number of alphabetic chars')
        raise
    return ret