οἶμαι δὲ οὐδὲ σοί, ἐὰν μὴ ἐγώ σοι μαρτυρῶ εἷς ὢν μόνος, τοὺς δ᾽ ἄλλους πάντας τούτους χαίρειν ἐᾷς.
I think neither have you (scil. achieved anything in your speech) unless I alone witness on your behalf and unless you say farewell to all other witnesses. I think that τοὺς δ᾽ ἄλλους πάντας τούτους χαίρειν ἐᾷς still depends on ἐὰν μὴ, the translations though have it differently: ’ and you have nothing to do’ or ‘you may let them go’ (the Russian translation).