#include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
bool check25(int b)
{
while(b%2==0)
b/=2;
while(b%5==0)
b/=5;
return b==1;
}
int main()
{
int a,b;
while(cin>>a>>b,b!=0)
{
int g=__gcd(a,b);
a/=g; b/=g;
if(check25(b))
{
cout<<1<<endl;
continue;
}
long long nine=9;
for(int i=1;;i++)
{
if(nine%b==0)
{
cout<<i<<endl;
break;
}
nine=nine%b*10+9;
}
}
}
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