def min(a, b)
  return b if a == nil
  return a if b == nil
  [a, b].min
end

def goodness(a, b, cost)
  a + b - cost
end

n = gets.to_i
c, v = gets.split.map(&:to_i)
ans = nil

q = [[1, 0, 0]]

n.times do

  r = []
  q.each do |a, b, cost|
    if a >= n
      ans = min(ans, cost)
    else
      r << [a + a, a, cost + c + v]
      r << [a + b, b, cost + v]
    end
  end

  q = r.sort_by {|a, b, cost| -goodness(a, b, cost)}[0...100]

end

p ans