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