#include <bits/stdc++.h>
using namespace std;
using namespace chrono;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif

int main() {
    int64_t a, b;
    cin >> a >> b;

    if (a > b) {
        swap(a, b);
    }
    b--;
    if (a > b) {
        swap(a, b);
    }

    cout << 2 * min(a, b) << endl;

    return 0;
}