Task: Sentence Expansion
Input (English): Mebyon Kernow – The Party for Cornwall ( , MK ; Cornish for " Sons of Cornwall " ) is a political party in Cornwall .
Output (English): Mebyon Kernow – The Party for Cornwall ( -RSB- , MK ; Cornish for " Sons of Cornwall " ) is a Cornish nationalist , centre-left political party in Cornwall , a county in the southwestern United Kingdom .