#include <stdio.h>
#define ll long long
#define rep(i,l,r)for(ll i=(l);i<(r);i++)

int main(){
	ll n,w,p;
	while(scanf("%lld%lld%lld",&n,&w,&p),n){
		ll s=0,d;
		rep(i,0,n){
			ll t;
			scanf("%lld",&t);
			s+=t;
			if(i+1==w)d=t;
		}
		printf("%lld\n",d?s*(100-p)/d:0);
	}
}
