cadet des soucis de

Noun

 * 1)  the least of (someone's) concerns, the least of (someone's) worries, the least thing on (someone's) mind

Usage notes

 * Always used with the definite article.
 * Chiefly used with personal determiners: le cadet de mes soucis, le cadet de tes soucis, le cadet de ses soucis, le cadet de nos soucis, le cadet de vos soucis, le cadet de leurs soucis.