#include<stdio.h>
int main(){
  int N,M,P,i,j=0,sum,res,result;
  int X[1000],en[1000];
  while(1){
    sum=0;
    res=0;
    scanf("%d%d%d",&N,&M,&P);
    if(N==0 && M==0 && P==0)break;
    for(i=0;i<N;i++){
      scanf("%d",&X[i]);
      sum+=X[i];
    }
    result=sum*100;
    res=result*(100-P)*0.01;
    if(X[M-1]==0)en[j]=0;
    else en[j]=res/X[M-1];
    j++;
  }
  for(i=0;i<j;i++)
    printf("%d\n",en[i]);
  return 0;
}