print((function (f)
	local a,s = {},io.stdin:read("*l")
	local i = #s%3==0 and 3 or #s%3
	f(a,s:sub(1,i)) for i=i+1,#s,3 do f(a,",") f(a,s:sub(i,i+2)) end
	return table.concat(a)
end)(table.insert))