If a number where the first digit is not zero reads the same from left to right as from right to left, we call it a palindrome number.

For example, given the decimal number ~56~, the sum of ~56+65~ (i.e. ~56~ read from right to left) is ~121~ which is a palindrome number.

Another example for decimal number ~87~:

STEP 1: ~87+78 = 165~

STEP 2: ~165+561 = 726~

STEP 3: ~726+627 = 1353~

STEP 4: ~1353+3531 = 4884~

A step here refers to one addition done in base ~N~. The above example used ~4~ steps to get a palindrome number, ~4884~.

Given the base ~N~ ~(2 \le N \le 10 \text{ or } N = 16)~ and the initial number ~M~ (less than or equal to ~100~ digits) in base ~N~, find the minimum steps to get a palindrome number. If it is impossible to get a palindrome number in less than or exactly ~30~ steps, output Impossible!.

Input Specification

The first line will contain ~N~.

The second line will contain ~M~.

Output Specification

If you can get a palindrome number within ~30~ steps, output the number of steps in the form of STEP=ans, where ans is the minimum number of steps to get a palindrome number. Otherwise, output Impossible!.

Sample Input

10
87

Sample Output

STEP=4

Problem translated to English by Tommy_Shan.