#include <iostream>
using namespace std;

int N, M, P, S, T;

int main() {
	while (1) {
		cin >> N >> M >> P;
		if (!(N | M | P)) break;
		S = 0; T = 0;
		for (int i = 1; i <= N; i++) {
			int x; cin >> x;
			if (i == M) T = x;
			S += x;
		}
		if (T) printf("%d\n", S * (100 - P) / T);
		else printf("0\n");
	}
	return 0;
}