#!/bin/python3

import math

import os

import random

import re

import sys

#

# Complete the 'appendAndDelete' function below.

#

# The function is expected to return a STRING.

# The function accepts following parameters:

# 1. STRING s

# 2. STRING t

# 3. INTEGER k

#

def appendAndDelete(s, t, k):

if k >= len(s) + len(t):

return 'Yes'

counter = 0

for i in range(min(len(s), len(t))):

if s[i] == t[i]:

counter += 1

else:

break

print(counter, len(s) + len(t))

if counter == 0 and len(s) + len(t) <= k:

return 'Yes'

elif len(s) + len(t) - counter*2 == k:

return 'Yes'

elif (counter == len(s) or counter == len(t)) and (k-abs(len(s)-len(t)))%2 == 0:

return 'Yes'

else:

return 'No'

if __name__ == '__main__':

fptr = open(os.environ['OUTPUT_PATH'], 'w')

s = input()

t = input()

k = int(input().strip())

result = appendAndDelete(s, t, k)

fptr.write(result + '\n')

fptr.close()