#20131114

while true
	n,m,p = gets.split(" ").map{|e|e.to_i}
	break if n==0 && m==0 && p==0
	array=[]
	count=0
	n.times{|t|
		array.push gets.to_i
		count+=array[t]
	}
	money = count*(100-p)
	p money/array[m-1] if array[m-1] != 0
	p 0 if array[m-1] == 0

end