In the present world you frequently meet a lot of call numbers and they are going to be longer and longer. You need to member such a kind of numbers. One method how to do it in an easy way is to assign letters to digits as shown in the following picture:
1 ij 2 abc 3 def
4 gh 5 kl 6 mn
7 prs 8 tuv 9 wxy
0 oqz
This way every word or a group of words can be assigned a unique number, so you can remember words instead of call numbers. It is evident that it has its own charm if it is possible to find some simple relationship between the word and the person itself. So you can earn that the call number 941837296 of a chess playing friend of yours can be read as WHITEPAWN, and the call number 2855304 of your favourite teacher is read BULLDOG.
Write a program to find the shortest sequence of words (i.e. one having the smallest possible number of words) which corresponds to a given number and a given list of words. The correspondence is described by the picture above.