#include <iostream>
#include <algorithm>
#include <vector>
#include <algorithm>

using namespace std;

vector<int> decompose(long long x) {
	vector<int> sol;
	while (x) {
		sol.push_back(x%10);
		x /= 10;
	}
	reverse(sol.begin(), sol.end());
	return sol;
}

void solve() {
	long long a, b;
	cin >> a >> b;

	if (a >= 10) {
		cout << 0 << "\n";
		return;
	}

	vector<long long> pw10(30);
	pw10[0] = 1;
	for (int i = 1; i <= 20; ++i) {
		pw10[i] = pw10[i-1] * (10-a);
	}


	vector<int> digs = decompose(b);

	long long ans = 0;
	for (int i = 0; i < digs.size(); ++i) {
		// cout << digs[i] << " ";
		ans += max(0LL, (digs[i]-1) - (a-1)) * pw10[digs.size()-i-1];
		if (i == 0) {
			for (int j = i; j+1 < digs.size(); ++j) {
				ans += pw10[digs.size()-j-1];
			}
		}
	}
	cout << ans << "\n";
}

int main() {
	int tests = 1;

	for (;tests; --tests) {
		solve();
	}
}