import nltk
import random
file = open('SMSm.txt', 'r')
file2 = open('SMSw.txt', 'w')
debited=[]
for line in file.readlines():
    if 'debited with' in line:
        import re
        a= re.findall(r'[INR]S*', line)
        debited.append(a)
        file2.write(line)

print re.findall(r'^(.*?)(=)?$', (debited)