#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: fzy001
	Language: C++
	Result: Accepted
	Time:16 ms
	Memory:2072 kb
****************************************************************/