#include<iostream>
#include<algorithm>
#include<cstdio>
#include<cstdlib>
#include<vector>
#include<map>
#include<queue>
#include<string>
#include<sstream>
#include<cmath>
#include<numeric>
using namespace std;

int main(){

  int a, b;
  cin >> a >> b;

  int m = 2000000000;

  if( a > b ) cout << m - b - 1 << endl;
  else if( a < b ) cout << b - 2 << endl;

  return 0;
}