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

const int INF = 1000000000;

int main() {
    int N, K, M;
    cin >> N >> K;
    cin >> M;

    vector<int> A(N + 1);
    long long 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;
    }

    long long 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) {
        cout << -1 << '\n';
        return 0;
    }

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

    int m = (int)(T - 1);

    vector<int> B(N + 1, 0);
    vector<int> rem(N + 1, 0);
    vector<int> deadline(N + 1, INF);
    vector<int> deadline_count(max(1, m) + 1, 0);

    int sumB = 0;

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

        B[i] = b;
        rem[i] = b;
        sumB += b;

        if (b > 0) {
            int d = K + 1 - b;
            if (d < 1) {
                cout << -1 << '\n';
                return 0;
            }

            int effective_deadline = min(d, m);
            deadline[i] = effective_deadline;
            deadline_count[effective_deadline] += b;
        }
    }

    assert(sumB == m);

    if (m == 0) {
        cout << 1 << '\n';
        cout << M << '\n';
        return 0;
    }

    vector<int> slack(m + 1, INF);

    int pref = 0;
    for (int x = 1; x <= m; x++) {
        pref += deadline_count[x];

        slack[x] = x - pref;

        if (slack[x] < 0) {
            cout << -1 << '\n';
            return 0;
        }
    }

    assert(pref == m);

    vector<int> ans;
    ans.reserve((size_t)T);

    for (int p = 1; p <= m; p++) {
        int min_deadline = INF;
        for (int i = 1; i <= N; i++) {
            if (rem[i] > 0) {
                min_deadline = min(min_deadline, deadline[i]);
            }
        }

        if (min_deadline < p) {
            cout << -1 << '\n';
            return 0;
        }

        int E = m + 1;
        for (int x = p; x <= m; x++) {
            if (slack[x] == 0) {
                E = x;
                break;
            }
        }

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

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

        ans.push_back(c);

        for (int x = p; x < deadline[c]; x++) {
            slack[x]--;
            if (slack[x] < 0) {
                cout << -1 << '\n';
                return 0;
            }
        }

        rem[c]--;
    }

    for (int i = 1; i <= N; i++) {
        assert(rem[i] == 0);
    }

    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;
}