K,A,B = gets.split.map(&:to_i)

count = 1
if A + 2 < B
    k = K

    k -= A - 1
    count += A - 1

    if k.even?
        count += (k/2)*(B-A)
    else
        count += (k/2)*(B-A)+1
    end
else
    count += K
end

puts count
