#include <stdio.h>
int main(void)
{
  int n,m,p,i,sum,ans;
  while(1){
    scanf("%d %d %d",&n,&m,&p);
    if(!(n+m+p)) break;
    int a[n];
    sum=0;
    for(i=0;i<n;i++){
      scanf("%d",&a[i]);
      sum+=a[i];
    }
    sum*=100;
    sum=sum-sum*p/100;
    if(!a[m])
      printf("%d\n",0);
    else{
      ans=sum/a[m];
      printf("%d\n",ans);
    }
    }
  return 0;
}