One day Misha and Andrew were playing a very simple game. First, each player chooses an integer in the range from 1 to *n*. Let's assume that Misha chose number *m*, and Andrew chose number *a*.

Then, by using a random generator they choose a random integer *c* in the range between 1 and *n* (any integer from 1 to *n* is chosen with the same probability), after which the winner is the player, whose number was closer to *c*. The boys agreed that if *m* and *a* are located on the same distance from *c*, Misha wins.

Andrew wants to win very much, so he asks you to help him. You know the number selected by Misha, and number *n*. You need to determine which value of *a* Andrew must choose, so that the probability of his victory is the highest possible.

More formally, you need to find such integer *a* (1 ≤ *a* ≤ *n*), that the probability that is maximal, where *c* is the equiprobably chosen integer from 1 to *n* (inclusive).

The first line contains two integers *n* and *m* (1 ≤ *m* ≤ *n* ≤ 10^{9}) — the range of numbers in the game, and the number selected by Misha respectively.

Print a single number — such value *a*, that probability that Andrew wins is the highest. If there are multiple such values, print the minimum of them.

In the first sample test: Andrew wins if *c* is equal to 2 or 3. The probability that Andrew wins is 2 / 3. If Andrew chooses *a* = 3, the probability of winning will be 1 / 3. If *a* = 1, the probability of winning is 0.

In the second sample test: Andrew wins if *c* is equal to 1 and 2. The probability that Andrew wins is 1 / 2. For other choices of *a* the probability of winning is less.

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