n,a,b = map(int,input().split())
ans = a * (n-1) - b * n

if n % 2 == 0:
	ans = min(ans, - a * (n-1))
	ans = min(ans, - a * (n-3) - b * 2)
else:
	ans = min(ans, - a * (n-1) - b)

print(ans)