#include <stdio.h>

int main(void) {
	int N,M,P;
	int i;
	int now;
	int sum;
	int winner;
	while(1) {
		scanf("%d%d%d",&N,&M,&P);
		if(N==0 && M==0 && P==0)break;
		sum=winner=0;
		for(i=0;i<N;i++) {
			scanf("%d",&now);
			sum+=now;
			if(i+1==M)winner=now;
		}
		printf("%d\n",winner?sum*100*(100-P)/100/winner:0);
	}
	return 0;
}