Padam Padam... The Sound of His and Her Heartbeats (Padam Padam ... Keuwa Keunyeoui Shimjangbakdongsori / 빠담빠담…. 그와 그녀의 심장박동소리)

Perfectly synced for all versions (bigger and smaller) of episode 18. Enjoy:):):) {Not mine I've just uploaded It}