def appendAndDelete(s, t, k):
    # Write your code here
    
    #all cases where the length of the two strings combined is less than or equal to k work
    if len(t) + len(s) <= k:
        return 'Yes'
    
    index=0
		
    while True:
        
        #remove the out of index range scenario
        if index > len(s) - 1 or index > len(t) - 1:
            break
        #determine up to which index is the same
        if s[index] == t[index]:
            index+=1
        else:
            break
            
    #determine remaining steps needed and if the difference between remaining and k is either 0 or even
     
    remaining_steps = len(s) + len(t) - index * 2
    if remaining_steps <= k and (k - remaining_steps) % 2 == 0:
        return 'Yes'
    else:
        return 'No'