#include <stdio.h>

int main(void) {
	int a,b,c,s,i,h,n;
	while(scanf("%d%d%d",&a,&b,&c) , a != 0){
		s = 0;
		for(i = 1;i <= a;i++){
			scanf("%d\n",&n);
			if(i == b) h = n;
			s+=n;
		}
		if(h)printf("%d\n",(s*(100-c))/h);
		else printf("0\n");
	}
	return 0;
}