[Aetae]

<input type="text" pattern="[А-ЖИК-ЩЭ-Яа-жик-щэ-я\d \\]+" onkeydown="var reg = /^[а-жик-щэ-я\d \\]$/i; if(event.key.length == 1 && !reg.test(event.key)) event.preventDefault();">