A building's elevator security system assigns every floor f an access code equal to f itself. During a nightly maintenance window covering floors m through n inclusive, the system computes a combined lockout mask by taking the bitwise AND of every floor's access code in that window.
Given m and n, compute this AND of all integers from m to n inclusive.
Input format
Line 1: two space-separated integers m n.
Output format
A single integer: the bitwise AND of every integer in [m, n].
Constraints
- 0 ≤ m ≤ n ≤ 2,000,000