import java.util.Scanner; 

public class Main { 
public static int digitCounts(int n, int k) { 
int count=0; 
if(n%10>=k) 
count++; 
for(int i=10;i<=n;i*=10){ 
count+=n/i*i/10; 
if((n%(i*10))/i==k) 
count+=n%i+1; 
if((n%(i*10))/i>k) 
count+=i; 
if(k==0) 
count-=i; 
} 
return count; 

} 


public static void main(String[] args) { 
Scanner input = new Scanner(System.in); 
int n = input.nextInt(); 
int k = input.nextInt(); 
System.out.println(digitCounts(n, k)); 
} 
}