a = gets.split.map(&:to_i)
a.sort!
res = a[0]
2.downto(0){|i| a[i] -= a[0]}
while true do
    d = a[2] / 3
    if d == 0
        break
    elsif a[1] <= d
        res += a[1]
        a[2] -= a[1] * 3
        a[1] -= a[1]
        break
    end
    res += d
    a[1] -= d
    a[2] -= d * 3
    a.sort!
end
res += a[2] / 5
puts res