import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
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n, a, b = na()
x = - n * b + (n-1)* a
f = (n-1)//2
y = - a * f * 2 + a * (n - 1 - f * 2) + b * f - b * (n - f)
if n % 2 == 0:
    z = - a * (n - 1)
else:
    z = 10000
print(min(x,y,z))