ни бе ни ме

ни бе ни ме <ни кукареку> (не знать, не смыслить и т. п.)

прост.

not to know a thing; cf. not to know beans; not to know head or tail about smth.; not to know B (a B) from a battledore (from a bull's foot, from a buffalo foot, from a broomstick); not to know chalk from cheese

- Настоящее моё дело - скот разводить. Через скот людям помогать жить, а не припарами да микстурами, в которых я ни бе ни ме. (Л. Соболев, Зелёный луч) — 'My real calling was stock-raising. I wanted to help people to live not by giving them poultices and mixtures I didn't know head or tail about but through raising good cattle.'