#include <iostream>
#include <vector>
#include <algorithm>
using namespace std;
int main()
{
        long long m;
        int n;
        cin >> m >> n;





        int nums[10], sznums = 0, r = 10, need = 1, cnt = 0;
        for (int i = 1; i <= n; i++)r *= 10, need *= 2;




        for (int i = 1; i <= r; i++)
        {
            int cur = 0, prev = i, tt = n, a = prev;
            while (1)
            {
                while (tt&&a > 0)
                {
                    nums[sznums] = a % 10;
                    sznums++;
                    a /= 10;
                    tt--;
                }
                prev--;
                if (!tt || prev == 0)break;
                a = prev;
            }



            for (int j = sznums - 1; j >= 0; j--)cur = cur * 10 + nums[j];

            sznums = 0;
            if (cur%need == 0)cnt++;
        }


        long long ans = (long long)(m / r)*(long long)cnt;



        bool ttt = false;
        if (m < r)ttt = true;
        for (int i = 1; i <= (m%r); i++)
        {
            int cur = 0, prev = i, tt = n, a = prev;
            while (1)
            {
                while (tt&&a > 0)
                {
                    nums[sznums] = a % 10;
                    sznums++;
                    a /= 10;
                    tt--;
                }
                if (ttt == false)break;
                prev--;
                if (!tt || prev == 0)break;
                a = prev;
            }


            for (int j = sznums - 1; j >= 0; j--)cur = cur * 10 + nums[j];

            sznums = 0;
            if (cur%need == 0)ans++;
        }


        cout<<ans;
    return 0;
}