#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,b) for(int i=a;i<b;i++)
typedef long long ll;

int main()
{
	ll A, B;
	cin >> A >> B;
	ll max = 2;
	rep(i, 0, 9) max *= 10;

	if (A < B)
		cout << (B - 2) << endl;
	else
		cout << (max - B - 1) << endl;
}