You are given a string str and array of string vec. You have to tell whether you can acheive str by combination of strings in vec. You need to use each string of vec atmost once. vec may contain the repeating strings.

constraints: 1<=str.length<=300 1<= vec.length <= 1000 1 <= vec[i].length <=20

Sample Input :

codeit
2
code
it

Sample Output:

yes

Please give me the idea to solve.... Thank you in advance