#include <stdio.h>

/** Application main entry point. */
int main (
  int     argc,
  char  * argv[ ]
  )
{
  int i;

  for ( ; ; )
  {
    int n, m, p;
    int res = 0, divisor = 1;

    scanf ( "%d%d%d", &n, &m, &p );
    if ( !( n | m | p ) ) break ;

    for ( i = 1; i <= n; ++i )
    {
      int t;

      scanf ( "%d", &t );
      if ( i == m ) divisor = t;
      res += t;
    }
    res *= ( 100 - p );

    printf ( "%d\n", ( divisor ? res / divisor : 0 ) );
  }

  return ( 0 );
}