Input

An integer n, denoting number of words to follow n words separated by whitespace.

Processing? Write this in Java

The program checks to make sure that each word (other than the first) begins with the last letter of the previous word.

Output

If each word in the sequence begins with the last letter of the previous word, then your program should print

Valid 

If one of the words (except the first) does not begin with the last letter of the previous word, your program should print

Invalid: NEXT does not follow PREV 

where NEXT is the first word in the sequence that does not start with the last letter of the preceding word PREV.

Sample Input Sample Output 3 Hello other requests Valid 3 Hello world there Invalid: world does not follow Hello