C++ :

#include <iostream>
#include<cmath>
using namespace std;
#define ll unsigned long long
ll X, K,L;
const int MAX = 0x3f3f33f;
ll **s; // 0:最小值  1:sum  2:max  3:min
//求s[K][0]
void cal(ll k,ll x)
{
    s[k][1] = 0, s[k][2] = 0, s[k][3] = MAX;
    while (x)
    {
        s[k][1] += x % 10;
        s[k][2] = max(s[k][2], x % 10);
        s[k][3] = min(s[k][3], x % 10);
        x /= 10;
    }
}
void init()
{
    int m=ceil(log(X+1)/log(10.0));
    L=m*81+9;
    if(L<171)
        L=171;
    s=new ll*[L+1];
    for(ll i=0; i<=L; i++)
    {
        s[i] = new ll[4];
        if(i==0)
        {
            s[0][0]=0;
            cal(0,X);
        }
        else
        {
            s[i][0] = MAX;
            cal(i,i);
        }
    }
}
void quancheng()
{
    init();
    if (X == K)
    {
        cout<<"0"<<endl;
        return;
    }
    else if (K > L)
    {
        cout<<"No answer"<<endl;
        return;
    }
    bool flag = true;
    while (flag)
    {
        flag = false;
        for (int i = 0; i <= L; i++)
        {
            if (s[i][0] < MAX)
            {
                for (int j = 0; j <= L; j++)
                {
                    if (s[j][0] < MAX)
                    {
                        int a = s[i][1] * s[j][2] + s[j][3];
                        if (s[a][0] > s[i][0] + s[j][0] + 1)
                        {
                            s[a][0] = s[i][0] + s[j][0] + 1;
                            flag = true;
                        }
                    }
                }
            }
        }
    }
    if (s[K][0] < MAX)
        cout<<s[K][0]<<endl;
    else
        cout<<"No answer"<<endl;
}
int main()
{
    //freopen("input9.txt", "r", stdin);
    //freopen("output9.txt", "w", stdout);
    while (cin >> X >> K)
    {
        if (X == 0 && K == 0)
            break;
        quancheng();
    }
}