L = gets.to_i
M = gets.to_i
N = gets.to_i

sum_money = L * 100 + M * 25 * N * 1

coins_sum = sum_money % 1000

sum = 0
[100, 25].each do |i|
	num, money = coins_sum.divmod(i)
	sum += num
	coins_sum = money
end

puts sum