append-and-delete.py

#!/bin/python3

import sys

def appendAndDelete(s, t, k):
    start = 0
    ind = 0
    to_del = 0
    to_app = 0
    
    while ind < len(s) and ind < len(t) and s[ind] == t[ind]:
        ind += 1
    start = ind
    
    if start < len(s):
        to_del = len(s[start:])
        if to_del == len(s) and k - to_del >= len(t):
            return 'Yes'
    if start < len(t):
        to_app = len(t[start:])
    k -= to_del + to_app
    
    #print("start = {} to_del = {} to_app = {} k = {}".format(start, to_del, to_app, k))
    if k == 0 or (k > 0 and k % 2 == 0) or k >= 2*len(t):
        return 'Yes'
    else:
        return 'No'
    

if __name__ == "__main__":
    s = input().strip()
    t = input().strip()
    k = int(input().strip())
    result = appendAndDelete(s, t, k)
    print(result)