print((function (f)
	return tostring(f()):sub(1,-3)
end)(function ()
	local ffi = require'ffi'
	local C,cd = ffi.C,ffi.new("long[1]")
	ffi.cdef 'int scanf(const char *, ...);'
	C.scanf("%ld",cd)
	return (cd[0]/3+cd[0]/5)*2
end))