#include<bits/stdc++.h>
using namespace std;
int a,b,cnt = 0;
int w[105],s[105];
int main()
{
	cin>>a>>b;
	for(int i=a;i<=b;i++)
	{
		int t = i,ws = 0,f = 0;
		while(t!=0)
		{
			ws++;
			w[ws] = t%10;
			t = t/10;
		}
		for(int j=1;j<=ws;j++)
		{
			if(w[j]==w[j+1]||w[j]+1>ws)
			{
				f = 1;
				break;
			}
			else
			{
				for(int l=1;l<=ws;l++)
				{
					for(int k=0;k<ws;k++)
					{
						if(w[j]==k)
						{
							s[k]++;
							if(s[k]==2)
							{
								f = 1;
							}
							break;
						}
					}
					if(f==1) break;
				}
			}
			if(f==1) break;
		}
		if(f==1) continue;
		else
		{
			cnt++;
		}
	}
	cout<<cnt;
	return 0;
}