CF595B.Pasha and Phone

普及/提高-

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题目描述

Pasha has recently bought a new phone jPager and started adding his friends' phone numbers there. Each phone number consists of exactly nn digits.

Also Pasha has a number kk and two sequences of length n/kn/k ( nn is divisible by kk ) a1,a2,...,an/ka_{1},a_{2},...,a_{n/k} and b1,b2,...,bn/kb_{1},b_{2},...,b_{n/k} . Let's split the phone number into blocks of length kk . The first block will be formed by digits from the phone number that are on positions 11 , 22 ,..., kk , the second block will be formed by digits from the phone number that are on positions k+1k+1 , k+2k+2 , ..., 2k2·k and so on. Pasha considers a phone number good, if the ii -th block doesn't start from the digit bib_{i} and is divisible by aia_{i} if represented as an integer.

To represent the block of length kk as an integer, let's write it out as a sequence c1c_{1} , c2c_{2} ,..., ckc_{k} . Then the integer is calculated as the result of the expression c110k1+c210k2+...+ckc_{1}·10^{k-1}+c_{2}·10^{k-2}+...+c_{k} .

Pasha asks you to calculate the number of good phone numbers of length nn , for the given kk , aia_{i} and bib_{i} . As this number can be too big, print it modulo 109+710^{9}+7 .

输入格式

The first line of the input contains two integers nn and kk ( 1<=n<=1000001<=n<=100000 , 1<=k<=min(n,9)1<=k<=min(n,9) ) — the length of all phone numbers and the length of each block, respectively. It is guaranteed that nn is divisible by kk .

The second line of the input contains n/kn/k space-separated positive integers — sequence a1,a2,...,an/ka_{1},a_{2},...,a_{n/k} ( 1<=a_{i}<10^{k} ).

The third line of the input contains n/kn/k space-separated positive integers — sequence b1,b2,...,bn/kb_{1},b_{2},...,b_{n/k} ( 0<=bi<=90<=b_{i}<=9 ).

输出格式

Print a single integer — the number of good phone numbers of length nn modulo 109+710^{9}+7 .

输入输出样例

  • 输入#1

    6 2
    38 56 49
    7 3 4
    

    输出#1

    8
    
  • 输入#2

    8 2
    1 22 3 44
    5 4 3 2
    

    输出#2

    32400
    

说明/提示

In the first test sample good phone numbers are: 000000, 000098, 005600, 005698, 380000, 380098, 385600, 385698.

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