class Otoshidama
    attr_reader :n, :m

    def initialize(n: 0, m: 0)
        @n, @m = n, m
    end

    def cause
        begin
            @n = Integer(gets.chomp)
            @m = Integer(gets.chomp)
        rescue
            
        end
    end

    def otoshidama(budget, children)
        (@n / @m) / 1000 * 1000
    end

    def result
        puts otoshidama(@n, @m)
    end

    def run
        cause
        result
    end
end

if $0 == __FILE__
    Otoshidama.new.run
end