Problem:
Score : 100 points

Problem Statement

You are parking at a parking lot. You can choose from the following two fee plans:

Plan 1: The fee will be A×T yen (the currency of Japan) when you park for T hours.

Plan 2: The fee will be B yen, regardless of the duration.

Find the minimum fee when you park for N hours.

Constraints

1≤N≤20

1≤A≤100

1≤B≤2000

All input values are integers.

Input

Input is given from Standard Input in the following format:

N A B

Output

When the minimum fee is x yen, print the value of x.

Sample Input 1

7 17 120

Sample Output 1

119

If you choose Plan 1, the fee will be 7×17=119 yen.

If you choose Plan 2, the fee will be 120 yen.

Thus, the minimum fee is 119 yen.

Sample Input 2

5 20 100

Sample Output 2

100

The fee might be the same in the two plans.

Sample Input 3

6 18 100

Sample Output 3

100

Solution in Ruby (2.3.3) (judge verdict: Accepted)

def geti; gets.to_i end
def getis; gets.split.map &:to_i end
def getin n;  n.times.map{geti}  end
def getisn n; n.times.map{getis} end
YES = "YES"; NO = "NO"; Yes = "Yes"; No = "No";

n,a,b = getis
p [n*a,b].min

__END__

a,b,c = getis
p [a,b,c].any?(&:even?) ? 0 : [a*b,b*c,c*a].min

a,b=getis
puts a > 0 ? 'Positive' : b >= 0 ? 'Zero' : (b - a) % 2 == 1 ? 'Positive' : 'Negative'