#include<iostream>
#include<stdio.h>
#include<algorithm>
#include<math.h>
#include<string>
#include<string.h>
using namespace std;
int n,key,ans=0;
int f(int x)
{
if(x==0) return 0;
if(x==key) return f(x/10)+1;
return f(x/10);
}
int main()
{
freopen("count.in","r",stdin);
freopen("count.out","w",stdout);
scanf("%d%d",&n,&key);
for(int i=1;i<=n;i++) ans=ans+f(i);
printf("%d\n",ans);
fclose(stdin);
fclose(stdout);
return 0;
}