v = gets.split.map(&:to_i).uniq.sort
if v.size != 4
    p 4
    exit
end
ans = 1000
3.upto(30) do |c|  
    2.upto(c - 1) do |b|
        1.upto(b - 1) do |a|
            dp = Array.new(31, 1000)
            dp[0] = 0
            [a, b, c].each do |x|
                1.upto(30) do |i|
                    dp[i] = [dp[i], dp[i - x] + 1].min if i >= x
                end
            end
            tmp = 0
            v.each do |x|
                tmp += dp[x]
            end
            ans = [ans, tmp].min
        end
    end
end
p ans