#include <stdio.h>
 
int main() {
  while (1) {
    int N, M, P;
    scanf("%d %d %d", &N, &M, &P);
    if (N == 0 && M == 0 && P == 0) break;
    int X[100];
    int sum = 0;
    for (int i = 0; i < N; i++) {
      scanf("%d", &X[i]);
      sum += X[i] * 100;
    }
    sum = sum * (100 - P) / 100;
    printf("%d\n\n\n\n", X[M - 1] == 0 ? 0 : sum / X[M - 1]);
  }
}
