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

using ll = long long;

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

    int N, K, M;
    cin >> N >> K;
    cin >> M;

    vector<int> A(N + 1);
    ll S = 0;
    for (int i = 1; i <= N; i++) {
        cin >> A[i];
        S += A[i];
    }

    if (S % (N + 1) != 0) {
        cout << -1 << '\n';
        return 0;
    }

    ll T = S / (N + 1);
    if (T < 1) {
        cout << -1 << '\n';
        return 0;
    }

    vector<int> W(N + 1);
    for (int i = 1; i <= N; i++) {
        W[i] = A[i] - T;
        if (W[i] < 0) {
            cout << -1 << '\n';
            return 0;
        }
    }

    if (W[M] < 1 || A[M] - 2 < K) {
        cout << -1 << '\n';
        return 0;
    }

    int m = (int)T - 1;

    vector<pair<int, int>> v;
    for (int i = 1; i <= N; i++) {
        int b = W[i] - (i == M ? 1 : 0);
        if (b < 0) {
            cout << -1 << '\n';
            return 0;
        }
        if (b > 0) v.push_back({b, i});
    }

    sort(v.begin(), v.end(), [&](auto a, auto b) {
        if (a.first != b.first) return a.first > b.first;
        return a.second < b.second;
    });

    int pref = 0;
    vector<int> mid;
    for (auto [b, id] : v) {
        pref += b;
        if (pref > K + 1 - b) {
            cout << -1 << '\n';
            return 0;
        }
        for (int k = 0; k < b; k++) mid.push_back(id);
    }

    sort(mid.begin(), mid.end());

    vector<int> ans = mid;
    ans.push_back(M);

    cout << ans.size() << '\n';
    for (int i = 0; i < (int)ans.size(); i++) {
        if (i) cout << ' ';
        cout << ans[i];
    }
    cout << '\n';

    return 0;
}