CF478E.Wavy numbers

普及/提高-

通过率:0%

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题目描述

A wavy number is such positive integer that for any digit of its decimal representation except for the first one and the last one following condition holds: the digit is either strictly larger than both its adjacent digits or strictly less than both its adjacent digits. For example, numbers 3527035270 , 102102 , 747747 , 2020 and 33 are wavy and numbers 123123 , 10001000 and 22122212 are not.

The task is to find the kk -th smallest wavy number rr that is divisible by nn for the given integer values nn and kk .

You are to write a program that will find the value of rr if it doesn't exceed 101410^{14} .

输入格式

The only line of input contains two integers nn and kk , separated by a single space ( 1<=n,k<=10141<=n,k<=10^{14} ).

输出格式

Your task is to output the only integer rr — the answer to the given problem. If such number does not exist or it is larger than 101410^{14} , then print "-1" (minus one without the quotes) instead.

输入输出样例

  • 输入#1

    123 4
    

    输出#1

    1845
    
  • 输入#2

    100 1
    

    输出#2

    -1
    
  • 输入#3

    97461 457
    

    输出#3

    1805270103
    

说明/提示

The values of the first four wavy numbers that are divisible by nn for the first sample are: 492492 , 615615 , 738738 and 18451845 .

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