#include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int> >;
#define rep(i, n)         for(int i = 0; i < (int)(n); i++)
#define brep(n)           for(int bit=0;bit<(1<<n);bit++)
#define erep(i,container) for (auto i : container)
#define irep(i, n)        for(int i = n-1; i >= (int)0; i--)
#define rrep(i,m,n) for(int i = m; i < (int)(n); i++)
#define reprep(i,j,h,w) rep(i,h)rep(j,w)
#define all(x) (x).begin(),(x).end()
#define aall(x,n) (x).begin(),(x).begin()+(n)
#define VEC(type,name,n) std::vector<type> name(n);rep(i,n)std::cin >> name[i];
#define pb push_back
#define pf push_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define itn int
#define mp make_pair
#define sum accumulate
#define keta fixed<<setprecision
#define vvector(name,typ,m,n,a)vector<vector<typ> > name(m,vector<typ> (n,a))
#define vvvector(name,t,l,m,n,a) vector<vector<vector<t> > > name(l, vector<vector<t> >(m, vector<t>(n,a)));
#define vvvvector(name,t,k,l,m,n,a) vector<vector<vector<vector<t> > > > name(k,vector<vector<vector<t> > >(l, vector<vector<t> >(m, vector<t>(n,a)) ));
typedef long long ll;
const int INF = 2000000000;
const ll INF64 = 1000000000000000ll;
const ll MOD = 1000000007LL;
long long comb(int n, int r) {
	std::vector<std::vector<long long>> v(n + 1, std::vector<long long>(n + 1, 0));
	for (int i = 0; i < v.size(); i++) {
		v[i][0] = 1;
		v[i][i] = 1;
	}
	for (int j = 1; j < v.size(); j++) {
		for (int k = 1; k < j; k++) {
			v[j][k] = (v[j - 1][k - 1] + v[j - 1][k]);
		}
	}
	return v[n][r];
}
int main(){
    string s;
    std::cin >> s;
    ll k;
    std::cin >> k;
    ll ans=0ll;
    while(k>0ll{
        rrep(i,1,s.size()){
            ans+=9ll*comb(i-1,k-1)*pow(9,k-1);
        }
       // std::cout << ans << std::endl;
        ans+=(s[0]-'0'-1)*comb(s.size()-1,k-1)*pow(9,k-1);
        k--;
     //   std::cout << ans << std::endl;
        if(s.size()==1)break;
        s=s.substr(1,s.size()-1);
    }
    ans++;
    std::cout << ans << std::endl;
}