Let's name the string abcdefghijklmnopqrstuvwxyz the alphabet, and let d be the distance between two elements in the alphabet defined by the absolute value of the difference of their indexes. For example:

We can extend d to strings of equal length as follows: given two strings sa, sb of equal length len, d(sa, sb) is the sum of the pairwise d(sa[i], sb[i]) for all index values (i) from 0 to len-1. For example:

We can now define a (closed) ball of center a given string and of (integer) radius. A point p (i.e. a string with letters in the alphabet and of same length as the center) is inside the ball if d(center, p) <= radius.

Find the number of points contained in the ball of center center and radius radius.

Example (Test 4): 2 ab

The points at distance less or equal to 2 of ab are: - at distance 0: ab - at distance 1: bb, aa, ac - at distance 2: cb, ad, bc, ba

For a total of 8 points contained in the (closed) ball of center ab and radius 2.

NB: Tests 1-7 cover simple cases and should help you debug your program. Tests 8-11 check the performance.

Input

Line 1: An integer radius, the radius of the ball. Line 2: A string center, the center of the ball.

Output

The number of points inside the ball of center center and radius radius.

Constraints

0 < radius <= 100 0 < length(center) < 20 0 <= answer <= 1e6 The string center contains only lowercase English letters.