Problem Description

A good monomial is a monomial consisting of digits and lowercase English letters, where a lowercase letter is multiplied by an integer coefficient between 1 and 999 inclusive. Note that the coefficient 1 is not omitted in a good monomial.
For example, 123a and 1z are good monomials, but 0a, 1000b, 123, 12ab, a123, and a are not good monomials.

Furthermore, the value of a good monomial is determined by substituting the values defined as follows:

• $ a=1000 $
• $ b=1000a $
• $\dots$
• $ z=1000y $

For example, the value of 123a is $ 123000 $, the value of 20b is $ 20000000 $, and the value of 1c is $ 1000000000 $.

Output the largest possible value of a good monomial that is less than or equal to $\alpha$ in the form of a good monomial.
It can be proven that such a value always uniquely exists under the constraints of this problem.

Input Format

The input is given from the standard input in the following format:

$\alpha$

Output Format

Output according to the instructions in the problem statement.

Sample Input and Output

Sample Input #1

123456789

Sample Output #1

123b

Sample Input #2

77777

Sample Output #2

77a

Sample Input #3

9982443539982448531000000007

Sample Output #3

9i

Notes/Hints

Constraints

• $1000\ \le\ \alpha\ <\ 10^{81}$
• $\alpha$ is an integer

Sample Explanation 1

123b = $ 123000000 $, which is the largest value of a good monomial that is less than or equal to $\alpha\ =\ 123456789$.

Sample Explanation 3

The input may not fit within a 64-bit integer.

见题面 Input 部分

见题面 Output 部分