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

using ll = long long;
const int INF = 1e9;

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<int> rem(N + 1), deadline(N + 1, INF);

    for (int i = 1; i <= N; i++) {
        rem[i] = W[i] - (i == M ? 1 : 0);
        if (rem[i] < 0) {
            cout << -1 << '\n';
            return 0;
        }

        if (rem[i] > 0) {
            deadline[i] = min(K + 1 - rem[i], m);
            if (deadline[i] < 1) {
                cout << -1 << '\n';
                return 0;
            }
        }
    }

    vector<int> ans;

    for (int p = 1; p <= m; p++) {
        int c = -1;

        for (int i = 1; i <= N; i++) {
            if (rem[i] > 0 && deadline[i] <= p) {
                c = i;
                break;
            }
        }

        if (c == -1) {
            for (int i = 1; i <= N; i++) {
                if (rem[i] > 0) {
                    c = i;
                    break;
                }
            }
        }

        if (c == -1) {
            cout << -1 << '\n';
            return 0;
        }

        int before = (p - 1) + (W[c] - rem[c]);
        if (before >= K) {
            cout << -1 << '\n';
            return 0;
        }

        ans.push_back(c);
        rem[c]--;
    }

    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;
}