#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
const ll MOD = 1000000007;
const ld PI = acos(-1);  
const ld EPS = 0.0000000001;
#define REP(i, n) for(ll i=0; i<(ll)(n); i++)
#define REPD(i, n) for(ll i=n-1; 0<=i; i--)
#define FOR(i, a, b) for(ll i=a; i<(ll)(b); i++)
#define FORD(i, a, b) for(ll i=a; (ll)(b)<=i; i--)
#define ALL(x) x.begin(), x.end()
#define MAX(x) *max_element(ALL(x))
#define MIN(x) *min_element(ALL(x))

vector<ll> fac, finv, inv;

ll combCalc(ll n, ll k){
    if(n<k) return 0;
    if(n<0 || k<0) return 0;
    return fac[n]*(finv[k]*finv[n-k]%MOD)%MOD;
}
ll comb(ll x, ll y){
    fac = finv = inv = vector<ll>(x+1);
    fac[0] = fac[1] = 1;
    finv[0] = finv[1] = 1;
    inv[1] = 1;
    for(int i=2; i<=x; i++){
        fac[i] = fac[i-1]*i%MOD;
        inv[i] = MOD-inv[MOD%i]*(MOD/i)%MOD;
        finv[i] = finv[i-1]*inv[i]%MOD;
    }
    return combCalc(x, y);
}
template<int MOD> struct Fp {
    long long val;
    constexpr Fp(long long v = 0) noexcept : val(v % MOD) {
        if (val < 0) val += MOD;
    }
    constexpr int getmod() { return MOD; }
    constexpr Fp operator - () const noexcept {
        return val ? MOD - val : 0;
    }
    constexpr Fp operator + (const Fp& r) const noexcept { return Fp(*this) += r; }
    constexpr Fp operator - (const Fp& r) const noexcept { return Fp(*this) -= r; }
    constexpr Fp operator * (const Fp& r) const noexcept { return Fp(*this) *= r; }
    constexpr Fp operator / (const Fp& r) const noexcept { return Fp(*this) /= r; }
    constexpr Fp& operator += (const Fp& r) noexcept {
        val += r.val;
        if (val >= MOD) val -= MOD;
        return *this;
    }
    constexpr Fp& operator -= (const Fp& r) noexcept {
        val -= r.val;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr Fp& operator *= (const Fp& r) noexcept {
        val = val * r.val % MOD;
        return *this;
    }
    constexpr Fp& operator /= (const Fp& r) noexcept {
        long long a = r.val, b = MOD, u = 1, v = 0;
        while (b) {
            long long t = a / b;
            a -= t * b; swap(a, b);
            u -= t * v; swap(u, v);
        }
        val = val * u % MOD;
        if (val < 0) val += MOD;
        return *this;
    }
    constexpr bool operator == (const Fp& r) const noexcept {
        return this->val == r.val;
    }
    constexpr bool operator != (const Fp& r) const noexcept {
        return this->val != r.val;
    }
    friend constexpr ostream& operator << (ostream &os, const Fp<MOD>& x) noexcept {
        return os << x.val;
    }
    friend constexpr Fp<MOD> modpow(const Fp<MOD> &a, long long n) noexcept {
        if (n == 0) return 1;
        auto t = modpow(a, n / 2);
        t = t * t;
        if (n & 1) t = t * a;
        return t;
    }
};
using mint = Fp<MOD>;
mint calc(ll N, ll K) {
    mint res = 1;
    for (long long n = 0; n < K; ++n) {
        res *= (N - n);
        res /= (n + 1);
    }
    return res;
}

string s;
int n, k;
ll solve(int i, int k, int smaller){
    if(i==n)
        if(k==0) return 1;
        else return 0;
    if(k==0) return 1;
    if(smaller)
        return comb(n-i, k) * pow(9, k);
    else{
        if(s[i]=='0') return solve(i+1, k, false);
        
        ll zero = solve(i+1, k, true);
        ll aida = solve(i+1, k-1, true)*(s[i]-'1');
        ll icchi = solve(i+1, k-1, false);
        return zero + aida + icchi;
    }
}
int main(){
    cin >> s >> k;
    n = s.size();
    cout << solve(0, k, false) << endl;
}

Measured memory_bytes: 256