def appendAndDelete(s, t, k):
    # Write your code here
    if len(s)+len(t)<=k:
        return 'Yes'
    i = 0
    while i < min(len(s), len(t)) and s[i] == t[i]:
        i += 1
    root_index = i
    delta = len(s) - root_index
    chars_to_add = len(t) - root_index
    remaining_ops = k-(delta+chars_to_add)
    if remaining_ops>=0 and remaining_ops%2==0: 
        return 'Yes'
    else: 
        return 'No'