#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(n);++i)
using namespace std;
typedef long long ll;
typedef pair<int, int> P;

int dp[105][4][2];

int main() {
	string s; cin >> s;
	int K; cin >> K;
	int n = s.size();
	dp[0][0][0] = 1;
	rep(i, n)rep(j, 4)rep(k, 2) {
		int nd = s[i] - '0';
		rep(d, 10) {
			int ni = i + 1, nj = j, nk = k;
			if (d != 0) nj++;
			if (nj > K) continue;
			if (k == 0) {
				if (nd > d) nk = 1;
				if (nd < d) continue;
			}
			dp[ni][nj][nk] += dp[i][j][k];
		}
	}
	int ans = dp[n][K][0] + dp[n][K][1];
	cout << ans << endl;
	return 0;
}