Problems

# Mathematical game

# Mathematical game

Consider a mathematical game, two players MDM dylayut moves in turn. Given natural number **N**. In one move, this number must be reduced by the value of some natural number which does not exceed the value of **M** so that the result remained non-negative. Losing someone who could not make a move. And the value of **M** selects a player who goes second. For a given **N** to find the smallest possible value of **M**, which gives the second player a real chance to win, or output **0** in a losing case.

**Input**

One number**N** (**N** < **10 ^{5}**).

**Output**

One number **M** - solution to the problem.

Input example #1

7

Output example #1

6