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)