#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <string>
#include <map>
#include <iterator>
#include <set>
#include <queue>
#include <bitset>
#include <cassert>

using namespace std;
using ll = long long;


int main() {

    ll A, B;
    cin >> A >> B;
    ll res = 0;
    if (A < B) {


        res += B - A - 1;
        res += A - 1;

    } else {
        res += 2000000000 - A;
        res += A - B - 1;
    }

    cout << res << endl;

    return 0;
}