#include<iostream>
#include<iomanip>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<algorithm>
#include<string>
#include<fstream>
#include<map>
#include<stack>
#include<cwchar>
#include<queue>
#include<vector>
//#include <stdlib.h>
//#include<windows.h>
//#include<conio.h>
using namespace std;
int main()
{
	int a,b;
	cin>>a>>b;
	int x=(9-a/100)*100+a;
	int y=(1-b/100)*100+b;
	int n=(9-a/10%10)*10+a;
	int m=(1-b/10%10)*10+b;
	int i=(9-a%10)*1+a;
	int j=(1-b%10)*1+b;
	int ans=0;
	ans=max(x-b,a-y);
	ans=max(ans,max(n-b,a-m));
	ans=max(ans,max(i-b,a-j));
	cout<<ans<<endl;
	return 0;
}