import std.stdio;
import std.algorithm;
import std.string;
import std.range;
import std.array;
import std.conv;
import std.complex;
import std.math;
import std.ascii;
import std.bigint;
import std.container;
import std.typecons;

auto readInts() {
	return array(map!(to!int)(readln().strip().split()));
}
auto readInt() {
	return readInts()[0];
}
auto readLongs() {
	return array(map!(to!long)(readln().strip().split()));
}
auto readLong() {
	return readLongs()[0];
}

const real eps = 1e-10;

void main(){
	while(true) {
		auto NMP = readInts();
		auto N = NMP[0];
		auto M = NMP[1];
		auto P = NMP[2];
		if(N == 0 && M == 0 && P == 0) {
			return;
		}
		int[] X;
		for(int i; i < N; ++i) {
			X ~= readInt();
		}
		auto sum = reduce!("a+b")(0, X);
		writeln(X[M-1] == 0 ? 0: sum * (100-P) / X[M-1]);
	}
}