A10761. Taxes

Mr. Funt now lives in a country with a very specific tax laws. The total income of mr. Funt during this year is equal to $n$ ( $n>=2$ ) burles and the amount of tax he has to pay is calculated as the maximum divisor of $n$ (not equal to $n$ , of course). For example, if $n=6$ then Funt has to pay $3$ burles, while for $n=25$ he needs to pay $5$ and if $n=2$ he pays only $1$ burle.

As mr. Funt is a very opportunistic person he wants to cheat a bit. In particular, he wants to split the initial $n$ in several parts $n_{1}+n_{2}+...+n_{k}=n$ (here $k$ is arbitrary, even $k=1$ is allowed) and pay the taxes for each part separately. He can't make some part equal to $1$ because it will reveal him. So, the condition $n_{i}>=2$ should hold for all $i$ from $1$ to $k$ .

Ostap Bender wonders, how many money Funt has to pay (i.e. minimal) if he chooses and optimal way to split $n$ in parts.

The first line of the input contains a single integer $n$ ( $2<=n<=2·10^{9}$ ) — the total year income of mr. Funt.

Print one integer — minimum possible number of burles that mr. Funt has to pay as a tax.