import sys, re

pat = re.compile('[0-9]+')

print 'Replacing decimal digits.'
while 1:
    target = raw_input('Enter a target line ("q" to quit): ')
    if target == 'q':
        break
    repl = raw_input('Enter a replacement: ')
    result = pat.sub(repl, target)
    print 'result: %s' % result