#include<stdio.h>
#define M 110

int main(void){
  int i;
  int n,m,p,x;
  int status[M];
  int pool;

  for(;;){
    scanf("%d%d%d",&n,&m,&p);
    if(n==0 && m==0 && p==0)
      break;

    for(i=0;i<n;i++){
      scanf("%d",&x);
      status[i]=x;
    }

    pool=0;
    for(i=0;i<n;i++)
      pool+=status[i]*(100-p);

    if(status[m-1]==0)
      printf("0\n");
    else
      printf("%d\n",pool/status[m-1]);
  }

  return 0;
}