#include <bits/stdc++.h>
using namespace std;

int main(void){
	int n, m, p, cnt, x, sum;
	while(true){
		cin >> n >> m >> p;
		if(!n&&!m&&!p) break;
		cnt = 0; sum = 0;
		for(int i = 0; i < n; ++i){
			cin >> x;
			sum += x;
			if(i == m-1) cnt = x;
		}
		if(cnt == 0){
			cout << 0 << endl;
			continue;
		}
		cout << sum * (100 - p) / cnt << endl;
	}
	return 0;
}
