#include<stdio.h>
#define SIZE 100
#define GOLD 100
int main()
{
  int n,m,p;
  int i;
  int x,num;
  int sum;
  while(1)
    {
      scanf("%d%d%d",&n,&m,&p);
      if((n==0)&&(m==0)&&(p==0)) break;
      sum=0;
      for(i=1;i<=n;i++)
	{
	  scanf("%d",&x);
	  sum+=x;
	  if(i==m) num=x;
	}
      if(num==0) printf("0\n");
      else printf("%d\n",sum*(100-p)*GOLD/(100*num));
    }
  return 0;
}