t = {}
t[1], t[2], t[3] = io.read("*n", "*n", "*n")
table.sort(t)
cnt, a, b = t[1], t[2] - t[1], t[3] - t[1]

plan13 = math.floor((b - a) / 2)
plan13 = math.min(plan13, math.floor(b / 3))
plan13 = math.min(plan13, a)
cnt = cnt + plan13
a = a - plan13
b = b - plan13 * 3

plan44 = math.floor(a / 4)
plan44 = math.min(plan44, b / 4)
cnt = cnt + plan44 * 2
a = a - plan44 * 4
b = b - plan44 * 4

if(1 <= a and 3 <= b) then
    cnt = cnt + 1
end
print(cnt)