def appendAndDelete(s, t, k):
    n_s = len(s)
    n_t = len(t)
    n_min = min(n_s, n_t)
    n_same = 0
    for i in range(n_min):
        if s[i] == t[i]:
            n_same += 1
        else:
            break
    n_s_diff = n_s - n_same
    n_t_diff = n_t - n_same

    if n_s + n_t <= k:
        return 'Yes'
    elif n_s_diff + n_t_diff <= k:
        if (n_s - n_s_diff) != 0:
            if ((k - n_s_diff) - n_t_diff) % 2 ==0:
                return 'Yes'
            else:
                return 'No'
        else:
            return 'Yes'
    else:
        return 'No'