#include <bits/stdc++.h>
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define mod 1000000007
//#define mod 3
#define ll long long
using namespace std;
ll a[100010],b[100010];
int main()
{
ll n,k,a0,an,diff,n0,n1,i,cnt=1;
cin>>n>>k;
for(i=0;i<n/k;i++)
cin>>a[i];
for(i=0;i<n/k;i++)
cin>>b[i];
for(i=0;i<n/k;i++)
{
an=pow(10,k);
diff=an % a[i];
if(diff!=0)
an=an-diff;
else
an=an-a[i];
a0=0;
//diff=a0 % a[i];
//if(diff!=0)
// a0=a0+(a[i]-diff);
n0=((an-a0)/a[i])+1;
a0=b[i]*pow(10,k-1);
diff=a0 % a[i];
if(diff !=0)
a0=a0+(a[i]-diff);
an=((b[i]+1)*pow(10,k-1))-1;
diff=an % a[i];
if(diff != 0)
an=an-diff;
n1=((an-a0)/a[i])+1;
//cout<<n0<<" "<<n1<<endl;
cnt=(cnt*((n0-n1)%mod))%mod;
}
cout<<cnt<<endl;
}
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