local ffi = require 'ffi'
local C = ffi.C
ffi.cdef 'int printf(const char *, ...);'

C.printf("%lu\n", (function (f, g, h)
	local h,r={[4]={1,f},[5]={1,f},[8]={1,f},[12]={3,h},[15]={2,g},[18]={1,f},[23]={1,f}},1ULL
	for i=1,26 do
		local n=io.stdin:read("*n")
		if h[i]~=nil then if n<h[i][1] then return 0ULL end r=r*h[i][2](n) end
	end
	return r
end)(function (n)
	return n
end, function (n)
	return n%2==0 and (n/2)^2 or math.floor(n/2)*(math.floor(n/2)+1)
end, function (n)
	function f(n) return (n-1)*n/2 end
	local r=f(n-1)
	for i=n-2,2,-1 do
		local t=f(i)*(n-i)
		if t>r then r=t elseif r<t then break end
	end
	return r
end))