Append and Delete

#!/bin/python3

import math
import os
import random
import re
import sys

# Complete the appendAndDelete function below.
def appendAndDelete(s, t, k):
    flag=0

    while(k):
        if len(s)==0:
            k=k-len(t)
            if k>=0:
                flag=1
                break
            else:
                break
        elif s in t:
            if s[0]==t[0]:
                if len(t)-len(s)==k:
                    flag=1
                    break
                elif len(t)-len(s)<k:
                    if len(s)%2==len(t)%2:  #if both are even or odd
                        if k%2==0:
                            flag=1
                    else:
                        if k%2!=0:
                            flag=1
                else:
                    break
        s=s[:-1]
        k-=1
    if flag==0:
        return 'No'
    return 'Yes'


if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    s = input()

    t = input()

    k = int(input())

    result = appendAndDelete(s, t, k)

    fptr.write(result + '\n')

    fptr.close()