#include <bits/stdc++.h>
using namespace std;
int main(){
    int n,i,a,b,c,d;
    cin>>n>>i;
    for(;n<=i;n++){
        if(n<1000){  
            a=n/100;
            b=n/10%10;
            c=n%10;
            if(a-b==b-c)    
                cout<<n<<endl;
        }
        else{
            a=n/1000;
            b=n/100%10;
            c=n/10%10;
            d=n%10;
            if(a-b==b-c&&b-c==c-d)  
                cout<<n<<endl;  
        }
    }
    return 0;
    }
/**************************************************************
	Problem: 1466
	User: wengsihan
	Language: C++
	Result: Accepted
	Time:19 ms
	Memory:2072 kb
****************************************************************/