#include <stdio.h>

int main(void) {
  int n, m, p, x[1000], i, sum;
  while (1) {
    scanf("%d%d%d", &n, &m, &p);
    if (n == 0 && m == 0 && p == 0) return 0;

    for (i = 0; i < n; i++)
      scanf("%d", &x[i]);

    sum = 0;
    for (i = 0; i < n; i++)
      sum += x[i] * 100;

    sum = sum * (100 - p) / 100;
    if (x[m - 1] == 0) printf("%d\n", 0);
    else printf("%d\n", sum / x[m - 1]);
  }
}