#include <cstdio>
#include <iostream>

using namespace std;

long long A, B, power[200], nr, ans;
int b[2000], i, n;

int main()
{
    cin >> A >> B;

    if(A>=10)
    {
        cout << 0 << '\n';
        return 0;
    }

    power[0] = 1;
    for(i=1; i<=19; ++i)
      power[i] = power[i-1] * (10-A);

    while(B)
    {
        b[++n] = B%10;
        B /= 10;
    }

    for(i=1; i<=n; ++i)
        if(b[i] > A)
            ans += (b[i]-A) * power[i-1];

    for(i=1; i<n; ++i)
        ans += power[i];

    cout << ans << '\n';

    return 0;
}