시간 제한 메모리 제한 제출 정답 맞은 사람 정답 비율
2 초 512 MB 4 2 2 50.000%

문제

For this problem, a sentence with n words is a sequence of n non-empty strings [w1, w2, . . . , wn]. Given a sentence, a valid typesetting of length L is a string of length exactly L which is formed by concatenating all the words in the sentence and inserting a positive number of spaces between each adjacent pair of words.

An aligned typesetting is a valid typesetting such that the number of spaces in between each adjacent pair of words is equal.

For example, given the sentence [harry, ron, hermione] and using _ to indicate a space:

  • the string __harry_ronhermione is not a valid typesetting;
  • the string harry_ron_____hermione is a valid typesetting of length 22 but it is not an aligned typesetting;
  • the string harry___ron___hermione is an aligned typesetting of length 22.

Darcy was given a sentence of n words and the desired length of typesetting L. Can you help him to figure out whether it is possible to construct an aligned typesetting of the desired length?

입력

The first line contains two integers n (1 ≤ n ≤ 106), which is the number of words, and L (0 ≤ L ≤ 106), which is the desired length of typesetting.

The next n lines describe the words. Each of these lines contains a single string wi, representing the ith word in the sentence. The word contains only lowercase letters and consists of at least 1 and at most 106 characters.

The total length of all the words in the sentence is guaranteed to be at most 106.

출력

Display if there is an aligned typesetting of the sentence with the given length.

예제 입력 1

3 8
harry
j
p

예제 출력 1

No

예제 입력 2

1 5
harry

예제 출력 2

Yes

예제 입력 3

3 22
harry
ron
hermione

예제 출력 3

Yes