import java.io.OutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.stream.IntStream;
import java.util.Arrays;
import java.io.IOException;
import java.io.Reader;
import java.io.InputStreamReader;
import java.util.OptionalInt;
import java.util.ArrayList;
import java.util.List;
import java.io.BufferedReader;
import java.util.Comparator;
import java.io.InputStream;

/**
 * Built using CHelper plug-in
 * Actual solution is at the top
 */
public class Main {
    public static void main(String[] args) {
        InputStream inputStream = System.in;
        OutputStream outputStream = System.out;
        MyInput in = new MyInput(inputStream);
        PrintWriter out = new PrintWriter(outputStream);
        AMagic solver = new AMagic();
        solver.solve(1, in, out);
        out.close();
    }

    static class AMagic {
        public void solve(int testNumber, MyInput in, PrintWriter out) {
            int n = in.nextInt();
            int K = in.nextInt();
            int[][] a = new int[n][];
            for (int i = 0; i < n; i++) {
                a[i] = new int[]{in.nextInt(), i + 1};
            }
            List<Integer> ans = new ArrayList<>();
            int[] cur = null;
            LOOP:
            while (true) {
                Arrays.sort(a, Comparator.comparingInt(x -> -x[0]));
                int[] last = null;
                for (int j = 0; j < n; j++) {
                    if (a[j] == cur) continue;
                    if (a[j][0]-- == 0) break LOOP;
                    ans.add(a[j][1]);
                    last = a[j];
                }
                cur = last;
            }
            if (solve(n, ans) <= K) {
                out.println(-1);
                return;
            }
            out.println(ans.size());
            printList(out, ans);
        }

        int solve(int n, List<Integer> ans) {
            int[][] dp = new int[ans.size() + 1][n];
            for (int[] d : dp) Arrays.fill(d, 1 << 29);
            Arrays.fill(dp[ans.size()], 0);
            for (int i = ans.size() - 1; i >= 0; i--) {
                for (int j = 0; j < n; j++) {
                    for (int k = 0; k < n; k++) {
                        if (ans.get(i) == j + 1 && j == k) continue;
                        dp[i][j] = Math.min(dp[i][j], dp[i + 1][k] + (j == k ? 0 : 1));
                    }
                }
            }
            return Arrays.stream(dp[0]).min().getAsInt();
        }

        static void printList(PrintWriter out, List<?> p) {
            for (int i = 0; i < p.size(); i++) {
                out.print(p.get(i) + (i == p.size() - 1 ? "\n" : " "));
            }
        }

    }

    static class MyInput {
        private final BufferedReader in;
        private static int pos;
        private static int readLen;
        private static final char[] buffer = new char[1024 * 8];
        private static char[] str = new char[500 * 8 * 2];
        private static boolean[] isDigit = new boolean[256];
        private static boolean[] isSpace = new boolean[256];
        private static boolean[] isLineSep = new boolean[256];

        static {
            for (int i = 0; i < 10; i++) {
                isDigit['0' + i] = true;
            }
            isDigit['-'] = true;
            isSpace[' '] = isSpace['\r'] = isSpace['\n'] = isSpace['\t'] = true;
            isLineSep['\r'] = isLineSep['\n'] = true;
        }

        public MyInput(InputStream is) {
            in = new BufferedReader(new InputStreamReader(is));
        }

        public int read() {
            if (pos >= readLen) {
                pos = 0;
                try {
                    readLen = in.read(buffer);
                } catch (IOException e) {
                    throw new RuntimeException();
                }
                if (readLen <= 0) {
                    throw new MyInput.EndOfFileRuntimeException();
                }
            }
            return buffer[pos++];
        }

        public int nextInt() {
            int len = 0;
            str[len++] = nextChar();
            len = reads(len, isSpace);
            int i = 0;
            int ret = 0;
            if (str[0] == '-') {
                i = 1;
            }
            for (; i < len; i++) ret = ret * 10 + str[i] - '0';
            if (str[0] == '-') {
                ret = -ret;
            }
            return ret;
        }

        public char nextChar() {
            while (true) {
                final int c = read();
                if (!isSpace[c]) {
                    return (char) c;
                }
            }
        }

        int reads(int len, boolean[] accept) {
            try {
                while (true) {
                    final int c = read();
                    if (accept[c]) {
                        break;
                    }
                    if (str.length == len) {
                        char[] rep = new char[str.length * 3 / 2];
                        System.arraycopy(str, 0, rep, 0, str.length);
                        str = rep;
                    }
                    str[len++] = (char) c;
                }
            } catch (MyInput.EndOfFileRuntimeException e) {
            }
            return len;
        }

        static class EndOfFileRuntimeException extends RuntimeException {
        }

    }
}



Measured memory_bytes: 28628