str = 'g fmnc wms bgblr rpylqjyrc gr zw fylb. rfyrq ufyr amknsrcpq ypc dmp. bmgle gr gl zw fylb gq glcddgagclr ylb rfyr'q ufw rfgq rcvr gq qm jmle. sqgle qrpgle.kyicrpylq() gq pcamkkclbcb. lmu ynnjw ml rfc spj.'
str.replace('k','m').replace('o','q').replace('e','g')


alp = 'abcdefghijklmnopqrstuvwxyzabc'
def (ch):
    for i in range(0,len(alp)):
        if(alp[i] == ch):
            return i
    return -1
def addTwo(ch):
    for i in range(0,len(alp)):
        if(alp[i] == ch):
            return alp[i+2]

for i in str:
    ans = addTwo(i)
    if ans != None:
        print(addTwo(i),end='')
    else:
        print(i,end='')

import string
text = """g fmnc wms bgblr rpylqjyrc gr zw fylb. rfyrq ufyr
... amknsrcpq ypc dmp. bmgle gr gl zw fylb gq glcddgagclr ylb rfyr'q
 ... ufw rfgq rcvr gq qm jmle. sqgle qrpgle.kyicrpylq() gq pcamkkclbcb.
... lmu ynnjw ml rfc spj."""
table = string.maketrans(
...   string.ascii_lowercase,
...   string.ascii_lowercase[2:]+string.ascii_lowercase[:2])

.join([chr(ord(x)+2) for x in 'map'])

p = {}
with open("hehe.html","r") as f:
    for k,s in zip(f,range(0,1000000000000000)):
        for j in k:
            if j in p:
                p[j] = p[j] + 1
            else:
                p[j] = s


ans = sorted(p.items(),key=lambda d:d[1],reverse = False)
for ps in range(0,len(ans)):
    if ans[ps][1] < 2000:
        print(ans[ps][0],end='')

s = ''.join([line.rstrip() for line in open('hehe.html')])
OCCURRENCES = {}
for c in s: OCCURRENCES[c] = OCCURRENCES.get(c, 0) + 1
avgOC = len(s) // len(OCCURRENCES)
print (''.join([c for c in s if OCCURRENCES[c] < avgOC]) )               # equality

...

print ("".join([char for char in mess if char.isalpha()]))

...

print (re.sub(r'[^a-z]', '', str))