#include <bits/stdc++.h>
#define PI 3.14159265359
using namespace std;
const int64_t MOD = 1e9 + 7;

int main() {
	int64_t A, B;
	cin >> A >> B;

	if (A < B) {
		cout << A - 1 + B - A - 1 << endl;
	}
	else {
		cout << 2000000000 - A + A - B - 1 << endl;
	}
}