//#pragma comment(linker, "/STACK:16777216") //for c++ Compiler

#include <stdio.h>

#include <iostream>

#include <fstream>

#include <cstring>

#include <cmath>

#include <stack>

#include <string>

#include <map>

#include <set>

#include <list>

#include <queue>

#include <vector>

#include <algorithm>

#define Max (a,b) (((a) > (b)) ? (a) : (b))

#define Min (a,b) (((a) < (b)) ? (a) : (b))

#define Abs (x) (((x) > 0) ? (x) : (-(x)))

#define MOD 1000000007

#define pi acos(-1.0)

using namespace std;

typedef long long           ll      ;

typedef unsigned long long  ull     ;

typedef unsigned int        uint    ;

typedef unsigned char       uchar   ;

template <class T> inline void checkmin (T &a,T b) { if (a > b) a = b; }

template <class T> inline void checkmax (T &a,T b) { if (a < b) a = b; }

const double eps = 1e-      ;

const int N =               ;

const int M =          ;

const ll P = 10000000097ll   ;

const int INF = 0x3f3f3f3f   ;

int main(){

    int i, j, k, t, n, m, numCase = ;

    ll l, r;

    while (cin >> l >> r){

        for (i = ; i >= ; --i){

            if ((l & (1LL << i)) ^ (r & (1LL << i))) break;

        }

        ll ans = pow (, i + ) - ;

        cout << ans << endl;

    }

    return ;

}

A little girl loves problems on bitwise operations very much. Here's one of them.

You are given two integers l and r. Let's consider the values of  for all pairs of integers a and b (l ≤ a ≤ b ≤ r). Your task is to find the maximum value among all considered ones.

Expression  means applying bitwise excluding or operation to integers x and y. The given operation exists in all modern programming languages, for example, in languages C++ and Java it is represented as "^", in Pascal — as «xor».

The input consists of multiple test cases.

Each test case contains space-separated integers l and r (1 ≤ l ≤ r ≤ 1018).

In a single line print a single integer — the maximum value of  for all pairs of integers a, b (l ≤ a ≤ b ≤ r).

A little girl loves problems on bitwise operations very much. Here's one of them.

You are given two integers l and r. Let's consider the values of  for all pairs of integers a and b (l ≤ a ≤ b ≤ r). Your task is to find the maximum value among all considered ones.

Expression  means applying bitwise excluding or operation to integers x and y. The given operation exists in all modern programming languages, for example, in languages C++ and Java it is represented as "^", in Pascal — as «xor».

The input consists of multiple test cases.

Each test case contains space-separated integers l and r (1 ≤ l ≤ r ≤ 1018).

In a single line print a single integer — the maximum value of  for all pairs of integers a, b (l ≤ a ≤ b ≤ r).