proc getchar_unlocked():char {. importc:"getchar_unlocked",header: "" ,discardable.} proc scan(): int = while true: let k = getchar_unlocked() if k < '0': return result = 10 * result + k.ord - '0'.ord let a = scan() let b = scan() let c = scan() let d = scan() for i in a.countdown(0): if c * i > b : continue if i + c * i > d : continue quit $i,0