#include <stdio.h>
int main(){

  int i,n,m,p,num[100],mon,sum;

  while(scanf("%d%d%d",&n,&m,&p),n){
    sum=0;

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

    if(num[m-1]==0)printf("0\n");
    else{

      mon = (double)(sum*100*(100-p)/100)/num[m-1];

      printf("%d\n",mon);

    }
  }

  return 0;

}