Score : 400 points
We have an H-by-W matrix. Let a_{ij} be the element at the i-th row from the top and j-th column from the left. In this matrix, each a_{ij} is a lowercase English letter.
Snuke is creating another H-by-W matrix, A', by freely rearranging the elements in A. Here, he wants to satisfy the following condition:
Determine whether he can create a matrix satisfying the condition.
A palindrome is a string that reads the same forward and backward.
For example, a
, aa
, abba
and abcba
are all palindromes, while ab
, abab
and abcda
are not.
Input is given from Standard Input in the following format:
H W a_{11}a_{12}...a_{1W} : a_{H1}a_{H2}...a_{HW}
If Snuke can create a matrix satisfying the condition, print Yes
; otherwise, print No
.
3 4 aabb aabb aacc
Yes
For example, the following matrix satisfies the condition.
abba acca abba
2 2 aa bb
No
It is not possible to create a matrix satisfying the condition, no matter how we rearrange the elements in A.
5 1 t w e e t
Yes
For example, the following matrix satisfies the condition.
t e w e t
2 5 abxba abyba
No
1 1 z
Yes