/*
TASK:future
LANG:C++
*/
#include <iostream>

using namespace std;
char a[210],b[210],c[210],d[210];
int k,l,g,f,r,s,e[10][2],q,v,z;
int main()
{cin>>a>>b>>k;
 int n=strlen(a);
 int m=strlen(b);
 if(n==m)
 {       do
         {if(a[f]-'0'>b[f]-'0') g=1;
                 else if(a[f]-'0'<b[f]-'0') g=2;
                 f++;}
                 while(g==0||f==n-1);
                 if(g==0) g=1;
         if(g==1)
         {
                 for(int i=n-1;i>=0;i--)
        {l++;
                if(a[i]-'0'>=b[i]-'0') c[i]=((a[i]-'0')-(b[i]-'0'))+'0';
                else if(a[i]-'0'<b[i]-'0') 
                {
                     c[i]=(10-(b[i]-'0'))+'0';
                     if(a[i-1]-'0'>0) c[i-1]=((a[i-1]-'0')-1)+'0';
                     else if(a[i-1]-'0'==0) 
                     {
                          c[i-1]='9';
                          c[i-2]=((a[i-2]-'0')-1)+'0';
                     }
                }
        }}
        
        if(g==2)
         {
                 for(int i=n-1;i>=0;i--)
        {l++;
                if(b[i]-'0'>=a[i]-'0') c[i]=((b[i]-'0')-(a[i]-'0'))+'0';
                else if(b[i]-'0'<a[i]-'0') 
                {
                     c[i]=(10-(a[i]-'0'))+'0';
                     if(b[i-1]-'0'>0) c[i-1]=((b[i-1]-'0')-1)+'0';
                     else if(b[i-1]-'0'==0) 
                     {
                          c[i-1]='9';
                          c[i-2]=((b[i-2]-'0')-1)+'0';
                     }
                }
        }}
        
 }
 if(n>m)
 {for(int i=0;i<n-m;i++)
  d[i]='0';
  for(int i=n-m;i<n;i++)
  for(int j=0;j<m;j++)
  d[i]=b[j];
        for(int i=n-1;i>=0;i--)
        {l++;
            if(a[i]-'0'>=d[i]-'0') c[i]=((a[i]-'0')-(d[i]-'0'))+'0';
                else if(a[i]-'0'<d[i]-'0') 
                {
                     c[i]=(10-(d[i]-'0'))+'0';
                     if(a[i-1]-'0'>0) c[i-1]=((a[i-1]-'0')-1)+'0';
                     else if(a[i-1]-'0'==0) 
                     {
                          c[i-1]='9';
                          c[i-2]=((a[i-2]-'0')-1)+'0';
                     }
                     }
 }}
 if(n<m)
 {for(int i=0;i<m-n;i++)                                  //d-malko b-golqmo
  d[i]='0';
  for(int i=m-n;i<m;i++)
  for(int j=0;j<n;j++)
  d[i]=a[j];
        for(int i=n-1;i>=0;i--)
        {l++;
            if(b[i]-'0'>=d[i]-'0') c[i]=((b[i]-'0')-(d[i]-'0'))+'0';
                else if(b[i]-'0'<d[i]-'0') 
                {
                     c[i]=(10-(d[i]-'0')+(b[i]-'0'))+'0';
                     if(b[i-1]-'0'>0) c[i-1]=((b[i-1]-'0')-1)+'0';
                     r=1;
                     do
                     {
                         if((b[i-r]-'0')-1==0)
                         {
                                          c[i-r]='9';
                                          c[i-r-1]=((b[i-r-1]-'0'-1)+'0');
                                          r++;
                                          cout<<"b";
                         }
                         }
                         while((b[i-r]-'0')-1==0);             
                     }
 }}
 for(int i=0;i<l;i++)
 cout<<c[i];
 cout<<"0\n";     
 for(int i=0;i<l;i++)
 s=s+(c[i]-'0');
 for(int i=0;i<l;i++)  
 {
         if(c[i]-'0'==1&&s%(c[i]-'0')==0) e[1][0]++;
         if(c[i]-'0'==2&&s%(c[i]-'0')==0) e[2][0]++;
         if(c[i]-'0'==3&&s%(c[i]-'0')==0) e[3][0]++;
         if(c[i]-'0'==4&&s%(c[i]-'0')==0) e[4][0]++;
         if(c[i]-'0'==5&&s%(c[i]-'0')==0) e[5][0]++;
         if(c[i]-'0'==6&&s%(c[i]-'0')==0) e[6][0]++;
         if(c[i]-'0'==7&&s%(c[i]-'0')==0) e[7][0]++;
         if(c[i]-'0'==8&&s%(c[i]-'0')==0) e[8][0]++;
         if(c[i]-'0'==9&&s%(c[i]-'0')==0) e[9][0]++;
 }
 for(int i=1;i<10;i++)
 e[i][1]=i;
 int ok,t,t1;
 do
 {
     ok=1;
     for(int i=1;i<10;i++)
     if(e[i][0]<e[i+1][0])
     {
                    t=e[i][0];t1=e[i][1];
                    e[i][0]=e[i+1][0];e[i][1]=e[i+1][1];
                    e[i+1][0]=t;e[i+1][1]=t1;
                    ok=0;
     }
 }
 while(!ok);
 for(int i=l-1;i>=0;i--)
 {
         v=c[i]-'0';
         for(int j=1;j<10;j++)
         if(e[j][1]==v) z=e[j][0];
         if(s%(c[i]-'0')==0&&z==e[1][0]) {q=v;break;}
 }
 cout<<q<<"\n";
            
    
    return 0;
}
