#include<bits/stdc++.h>
using namespace std;
int max(int n)
{
	int b,a[8],s,i;
	while(n>0)
	{
		a[i]=n%10;
		s=s+1;
		n=n/10;
	}
	for(i=n;i>=s;i--)
	if (a[i]>=a[i-1]) return 0;
	return 1;
}
int main()
{
	int a,b,s,i;
	s=0;
	cin>>a;
	cin>>b;
	for(i=a;i<=b;i++)
	if(max(i)==1) s=s+1;
	cout<<a;	
}