#include<stdio.h>

int main(){
	int athlete_sum,winner_num,deduction,poll,poll_sum=0,winner_poll=0,i;
	
	scanf("%d %d %d",&athlete_sum, &winner_num, &deduction);

	while(athlete_sum!=0 && winner_num!=0 && deduction!=0){
	for(i=1;i<=athlete_sum;i++){
		scanf("%d",&poll);
		poll_sum+=poll;
		if(winner_num==i)
			winner_poll=poll;
	}

	if(winner_poll==0)
		printf("0\n");
	else
		printf("%d\n",(int)(double)((poll_sum*100)*(1-deduction*0.01))/winner_poll);

	scanf("%d %d %d",&athlete_sum, &winner_num, &deduction);
	poll_sum=0;
	winner_poll=0;
	}

	return 0;
}