#include<bits/stdc++.h> using namespace std; int a,b,j,s[1000005]; int pd(int x){ for(int i=x;i>=1;i/=10){ if(i%10==7)return 1; } return 0; } int main(){ cin>>a>>b; for(int i=a;i<=b;i++)if(i%7==0||pd(i)){s[j]=i;j++;} cout<<j<<endl; for(int i=0;i<j;i++)cout<<s[i]<<"\n"; return 0; }