Football Achievements#1261
The long-awaited World Cup has finally arrived. Many tourists, journalists, and others have traveled there. The main stars—the football players—have also arrived. Everything was ready, and the battle for the cup began.
Every evening, in order not to waste time, the football players gather in a room to play Mafia—not the usual version, but a football-themed one with novel twists. However, Lionel Messi and Cristiano Ronaldo even have no time for that. As always, they are arguing about who is better! To settle the debate, they called upon programmer Vasya (don't be surprised, footballers have their own quirks...), who used to play for Lviv's "Karpaty," but for obvious reasons did not make it to the World Cup finals, and asked him for help. Vasyl was quick-witted and immediately suggested a game to determine the winner!
The game is as follows: each footballer chooses a number—Ronaldo picks , Messi picks . Whoever first names the smallest number such that the product of all numbers from to is divisible by wins. To prevent tampering, Vasya was asked to check the correctness of the result. So, your task is to find given and .
The only line contains two integers and , named by the footballers and separated by a space.
1 \leq N, S \leq 10^9.
Output a single integer such that M \geq N. If no such number exists, output -1.
Example 1