Go: package main

import (
	"fmt"
	"math"
)

func main() {
	var M, N, P int
	for {
		fmt.Scan(&N, &M, &P)
		if N == 0 && M == 0 && P == 0 {
			return
		}

		arr := make([]int, N)
		sum := 0
		for i := 0; i < N; i++ {
			var po int
			fmt.Scan(&po)
			arr[i] = po
			sum += po
		}

		if arr[M-1] == 0 {
			fmt.Println(0)
		} else {
			fmt.Println(math.Floor(float64(sum * (100 - P) / arr[M-1])))
		}
	}
}

C++: #ifdef LOCAL
    #define _GLIBCXX_DEBUG
    #define __clock__
#else
    #pragma GCC optimize("Ofast")
#endif
#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using VI = vector<ll>;
using VV = vector<VI>;
using VS = vector<string>;
using PII = pair<ll, ll>;

// tourist set
template <typename A, typename B>
string to_string(pair<A, B> p);

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p);

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p);

string to_string(const string& s) {
  return '"' + s + '"';
}

string to_string(const char* s) {
  return to_string((string) s);
}

string to_string(bool b) {
  return (b ? "true" : "false");
}

string to_string(vector<bool> v) {
  bool first = true;
  string res = "{";
  for (int i = 0; i < static_cast<int>(v.size()); i++) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(v[i]);
  }
  res += "}";
  return res;
}

template <size_t N>
string to_string(bitset<N> v) {
  string res = "";
  for (size_t i = 0; i < N; i++) {
    res += static_cast<char>('0' + v[i]);
  }
  return res;
}

template <typename A>
string to_string(A v) {
  bool first = true;
  string res = "{";
  for (const auto &x : v) {
    if (!first) {
      res += ", ";
    }
    first = false;
    res += to_string(x);
  }
  res += "}";
  return res;
}

template <typename A, typename B>
string to_string(pair<A, B> p) {
  return "(" + to_string(p.first) + ", " + to_string(p.second) + ")";
}

template <typename A, typename B, typename C>
string to_string(tuple<A, B, C> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ")";
}

template <typename A, typename B, typename C, typename D>
string to_string(tuple<A, B, C, D> p) {
  return "(" + to_string(get<0>(p)) + ", " + to_string(get<1>(p)) + ", " + to_string(get<2>(p)) + ", " + to_string(get<3>(p)) + ")";
}

void debug_out() { cerr << '\n'; }

template <typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
  cerr << " " << to_string(H);
  debug_out(T...);
}

#ifdef LOCAL
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif
// tourist set end

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

#define FOR(i,a,b) for(ll i=(a);i<(b);++i)
#define rep(i,b) FOR(i, 0, b)
#define ALL(v) (v).begin(), (v).end()
#define p(s) cout<<(s)<<'\n'
#define p2(s, t) cout << (s) << " " << (t) << '\n'
#define br() p("")
#define pn(s) cout << (#s) << " " << (s) << '\n'
#define p_yes() p("YES")
#define p_no() p("NO")
#define SZ(x) ((int)(x).size())
#define SORT(A) sort(ALL(A))
#define RSORT(A) sort(ALL(A), greater<ll>())
#define MP make_pair

ll SUM(VI& V){
  return accumulate(ALL(V), 0LL);
}

void print_vector(VI& V){
  ll n = V.size();
  rep(i, n){
    if(i) cout << ' ';
    cout << V[i];
  }
  cout << endl;
}

ll gcd(ll a,ll b){
    if(b == 0) return a;
    return gcd(b,a%b);
}

ll lcm(ll a,ll b){
    ll g = gcd(a,b);
    return a / g * b;
}

void no(){p_no(); exit(0);}
void yes(){p_yes(); exit(0);}

const ll mod = 1e9 + 7;
const ll inf = 1e18;
const double PI = acos(-1);

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    // input
    ll n,m,p;;
    while(cin>>n>>m>>p){
      if(n==0) return 0;
      VI A(n);
      rep(i,n)cin>>A[i];
      ll sum = SUM(A) * 100;
      debug(sum);
      ll money = sum / 100 * (100-p);
      ll ret;
      if(A[m-1]==0){
        ret = 0;
      }else{
        ret = money/A[m-1];
      }
      p(ret);
    }    
    return 0;
}

C++: #include <iostream>
#include <string>
#include <queue>
#include <stack>
#include <algorithm>
#include <list>
#include <vector>
#include <complex>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <bitset>
#include <ctime>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <cassert>
#include <cstddef>
#include <iomanip>
#include <numeric>
#include <tuple>
#include <sstream>
#include <fstream>

using namespace std;
#define REP(i, n) for (int (i) = 0; (i) < (n); (i)++)
#define FOR(i, a, b) for (int (i) = (a); (i) < (b); (i)++)
#define RREP(i, a) for(int (i) = (a) - 1; (i) >= 0; (i)--)
#define FORR(i, a, b) for(int (i) = (a) - 1; (i) >= (b); (i)--)
#define DEBUG(C) cerr << #C << " = " << C << endl;
using LL = long long;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<LL>;
using VVL = vector<VL>;
using VD = vector<double>;
using VVD = vector<VD>;
using PII = pair<int, int>;
using PDD = pair<double, double>;
using PLL = pair<LL, LL>;
using VPII = vector<PII>;
#define ALL(a) begin((a)), end((a))
#define RALL(a) rbegin((a)), rend((a))
#define SORT(a) sort(ALL((a)))
#define RSORT(a) sort(RALL((a)))
#define REVERSE(a) reverse(ALL((a)))
#define MP make_pair
#define FORE(a, b) for (auto &&a : (b))
#define FIND(s, e) ((s).find(e) != (s).end())
#define EB emplace_back

const int INF = 1e9;
const int MOD = INF + 7;
const LL LLINF = 1e18;

void solve(int N, int M, int P) {
    VI X(N);
    REP(i, N) cin >> X[i];
    if (X[M - 1] == 0) {
        cout << 0 << endl;
        return;
    }
    cout << (accumulate(ALL(X), 0) * (100 - P)) / X[M - 1] << endl;
}

signed main(void) {
    int n, m, p;
    while (cin >> n >> m >> p) {
        if (n == 0 && m == 0 && p == 0) return 0;
        solve(n, m, p);
    }
}

C++: #include<bits/stdc++.h>

using namespace std;

int main()
{
  while(1){
    int N,M;
    double P;
    cin>>N;
    cin>>M;
    cin>>P;

    if(N == 0 && M == 0 && P == 0){
      break;
    }

    int sum_person = 0;
    vector<int> n;
    for(int i = 0;i < N;++i){
      int j = 0;
      cin>>j;
      n.push_back(j);
      sum_person += j;
    }

    double sum = 100 * sum_person;
    int getter = n.at(M-1);
    sum = sum * ((100-P) / 100);

    int ans = 0;
    if(getter != 0){
      ans = sum / getter;
    }
  
    cout<<ans<<endl;
  }

  return 0;
}

C++: #include <iostream>
#define REP(i, n) for(int (i) = 0; (i) < (n); (i)++)
using namespace std;

int main()
{
  int N, M, P;
  while(1){
    cin >> N >> M >> P;
    if(N == 0 && M == 0 && P == 0){
      break;
    }else{
      int x, y, sum;
      sum = 0, y = 0;
      REP(i, N){
        cin >> x;
        sum += x;
        if(i + 1 == M)
          y = x;
      }
      if(y)
        cout << sum * (100 - P) / y << endl;
      else
        cout << "0" << endl;
    }
  }
}

C++: #include <algorithm>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <map>
#include <math.h>
#include <set>
#include <stdio.h>
#include <string>
#include <vector>

using namespace std;

int main() {
  while (true) {
    int n, m, p;
    cin >> n >> m >> p;
    if (n == m && m == p && n == 0)
      break;
    vector<int> x(n);
    for (int i = 0; i < n; i++)
      cin >> x[i];
    long long sum = 0;
    for (int i = 0; i < n; i++)
      sum += x[i];
    sum *= (100 - p);
    if (x[m - 1] == 0)
      cout << 0 << endl;
    else
      cout << sum / x[m - 1] << endl;
  }

  return 0;
}