Virtual contest is a way to take part in past contest, as close as possible to participation on time. It is supported only ACM-ICPC mode for virtual contests.
If you've seen these problems, a virtual contest is not for you - solve these problems in the archive.
If you just want to solve some problem from a contest, a virtual contest is not for you - solve this problem in the archive.
Never use someone else's code, read the tutorials or communicate with other person during a virtual contest.

No tag edit access

E. Lucky Interval

time limit per test

4 secondsmemory limit per test

512 megabytesinput

standard inputoutput

standard outputPetya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not.

One day Petya came across an interval of numbers [*a*, *a* + *l* - 1]. Let *F*(*x*) be the number of lucky digits of number *x*. Find the minimum *b* (*a* < *b*) such, that *F*(*a*) = *F*(*b*), *F*(*a* + 1) = *F*(*b* + 1), ..., *F*(*a* + *l* - 1) = *F*(*b* + *l* - 1).

Input

The single line contains two integers *a* and *l* (1 ≤ *a*, *l* ≤ 10^{9}) — the interval's first number and the interval's length correspondingly.

Output

On the single line print number *b* — the answer to the problem.

Examples

Input

7 4

Output

17

Input

4 7

Output

14

Note

Consider that [*a*, *b*] denotes an interval of integers; this interval includes the boundaries. That is,

Codeforces (c) Copyright 2010-2017 Mike Mirzayanov

The only programming contests Web 2.0 platform

Server time: Mar/30/2017 23:27:04 (p1).

Desktop version, switch to mobile version.
User lists

Name |
---|