line = gets.chomp.split(" ").map(&:to_i)

k = line[0] + 1
a = line[1]
b = line[2]
diff = b - a

k = k - a

total = a
if diff <= 1
    total = k + a
elsif k % 2 == 0
    times = (k.to_f / 2).to_i
    total += diff * times
else
    times = ((k - 1).to_f / 2).to_i
    total += diff * times
    total += 1
end

puts total
