#include<stdio.h>

int main(){
	int i,n,m,p,x[128];
	double total=0;
	while(1){
		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]);
		for(i=0;i<n;i++)total+=x[i]*(100-p);
		if(x[m-1])printf("%d\n",(int)(total/(double)x[m-1]));
		else printf("0\n");
		total=0;
	}
	return 0;
}