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문제

The operation # is defined for any two positive integers.

If x and y are positive integers, then

(x#y) = sum_of_digits_in_x_decimal_notation × greatest_digit_in_y_decimal_notation + least_digit_in_y_decimal_notation

For example, (9#30) = 9×3+0 = 27, but (30#9) = 3×9+9 = 36.

Let us say that this problem's expression is such an expression which is either the single variable a (whose value is positive integer), or it can be written in the form (this problem's expression # this problem's expression).

For example, the following expressions are this problem's expressions:

  • a
  • (a#a)
  • ((a#a)#a)
  • (a#((a#a)#((a#a)#a)))

You are to write a program, which for the given value of a determines what is the least possible number of operations # with which this problem's expression with given value K (K - positive integer) can be written.

입력

From the keyboard two positive integer values are input - the value of integer variable a (1 ≤ a ≤ 999999999) and the value of the expression K (1 ≤ K ≤ 999999999).

출력

On the screen the least necessary number of operations # must be written. If for the given value of a it is impossible to obtain K as a value of this problem's expression , then the word 'NEVAR' must be written.

예제 입력 1

718 81

예제 출력 1

3

예제 입력 2

999 333

예제 출력 2

NEVAR