#include <bits/stdc++.h>
#pragma GCC diagnostic ignored "-Wsign-compare"
#pragma GCC diagnostic ignored "-Wsign-conversion"
#define NDEBUG
#define SHOW(...) static_cast<void>(0)
//!===========================================================!//
//!  dP     dP                          dP                    !//
//!  88     88                          88                    !//
//!  88aaaaa88a .d8888b. .d8888b. .d888b88 .d8888b. 88d888b.  !//
//!  88     88  88ooood8 88'  '88 88'  '88 88ooood8 88'  '88  !//
//!  88     88  88.  ... 88.  .88 88.  .88 88.  ... 88        !//
//!  dP     dP  '88888P' '88888P8 '88888P8 '88888P' dP        !//
//!===========================================================!//
template <typename T, typename A>
std::istream& operator>>(std::istream& is, std::vector<T, A>& v)
{
    for (auto& e : v) { is >> e; }
    return is;
}
template <typename T>
T read()
{
    T v;
    return std::cin >> v, v;
}
template <typename T>
std::vector<T> readVec(const std::size_t l)
{
    std::vector<T> v(l);
    for (auto& e : v) { std::cin >> e; }
    return v;
}
using ld = long double;
using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
constexpr unsigned int MOD = 1000000007;
template <typename T>
constexpr T INF = std::numeric_limits<T>::max() / 4;
template <typename F>
constexpr F PI = static_cast<F>(3.1415926535897932385);
std::mt19937 mt{std::random_device{}()};
template <typename T>
bool chmin(T& a, const T& b) { return (a > b ? a = b, true : false); }
template <typename T>
bool chmax(T& a, const T& b) { return (a < b ? a = b, true : false); }
template <typename T>
std::vector<T> Vec(const std::size_t n, T v) { return std::vector<T>(n, v); }
template <class... Args>
auto Vec(const std::size_t n, Args... args) { return std::vector<decltype(Vec(args...))>(n, Vec(args...)); }
template <typename T>
constexpr T popCount(const T u)
{
#ifdef __has_builtin
    return u == 0 ? T(0) : (T)__builtin_popcountll(u);
#else
    unsigned long long v = static_cast<unsigned long long>(u);
    return v = (v & 0x5555555555555555ULL) + (v >> 1 & 0x5555555555555555ULL), v = (v & 0x3333333333333333ULL) + (v >> 2 & 0x3333333333333333ULL), v = (v + (v >> 4)) & 0x0F0F0F0F0F0F0F0FULL, static_cast<T>(v * 0x0101010101010101ULL >> 56 & 0x7f);
#endif
}
template <typename T>
constexpr T log2p1(const T u)
{
#ifdef __has_builtin
    return u == 0 ? T(0) : T(64 - __builtin_clzll(u));
#else
    unsigned long long v = static_cast<unsigned long long>(u);
    return v = static_cast<unsigned long long>(v), v |= (v >> 1), v |= (v >> 2), v |= (v >> 4), v |= (v >> 8), v |= (v >> 16), v |= (v >> 32), popCount(v);
#endif
}
template <typename T>
constexpr T clog(const T v) { return v == 0 ? T(0) : log2p1(v - 1); }
template <typename T>
constexpr T msbp1(const T v) { return log2p1(v); }
template <typename T>
constexpr T lsbp1(const T v)
{
#ifdef __has_builtin
    return __builtin_ffsll(v);
#else
    return v == 0 ? T(0) : popCount((v & (-v)) - T(1)) + T(1);
#endif
}
template <typename T>
constexpr bool ispow2(const T v) { return popCount(v) == 1; }
template <typename T>
constexpr T ceil2(const T v) { return v == 0 ? T(1) : T(1) << log2p1(v - 1); }
template <typename T>
constexpr T floor2(const T v) { return v == 0 ? T(0) : T(1) << (log2p1(v) - 1); }
//!============================================!//
//!    8888ba.88ba             oo              !//
//!    88  '8b  '8b                            !//
//!    88   88   88  .d8888b.  dP  88d888b.    !//
//!    88   88   88  88'  '88  88  88'  '88    !//
//!    88   88   88  88.  .88  88  88    88    !//
//!    dP   dP   dP  '88888P8  dP  dP    dP    !//
//!============================================!//
int main()
{
    const int N = read<int>(), K = read<int>();
    std::vector<int> minus(N), M(N, K + 1);
    for (int i = 0, a; i < N; i++) { std::cin >> a, minus[i] = std::max(0, K + 1 - a); }
    const int S = std::accumulate(minus.begin(), minus.end(), 0);
    if (S > K) { return std::cout << -1 << std::endl, 0; }
    const int H = (K + 1) / 2;
    if (K == 0) {
        std::cout << N << std::endl;
        for (int j = 0; j < N; j++) { std::cout << j + 1 << " "; }
        std::cout << std::endl;
        return 0;
    }
    using P = std::pair<int, int>;
    std::priority_queue<P, std::vector<P>, std::greater<P>> Q;
    for (int i = 0; i < N; i++) { Q.push({minus[i], i}); }
    for (int i = 0; i < K - S; i++) {
        const auto p = Q.top();
        Q.pop(), Q.push({++minus[p.second], p.second});
    }
    for (int i = 0; i < N; i++) {
        if (minus[i] > H) { return std::cout << -1 << std::endl, 0; }
    }
    const int maxi = std::max_element(minus.begin(), minus.end()) - minus.begin();
    const int Max = minus[maxi];
    auto Seg = Vec(Max, 1, maxi);
    for (int j = 0, p = 0; j < N; j++) {
        if (maxi == j) { continue; }
        for (int k = 0; k < minus[j]; k++, (p += 1) %= Max) { Seg[p].push_back(j); }
    }
    SHOW(Seg);
    std::vector<int> T;
    for (int i = 0; i < Max; i++) {
        for (const int e : Seg[i]) { T.push_back(e); }
    }
    SHOW(T);
    std::vector<int> ans, perm(N);
    std::iota(perm.begin(), perm.end(), 0);
    ans = perm, std::swap(ans[T[0]], ans[N - 1]);
    for (int i = 0; i < K; i++) {
        auto p = perm;
        std::swap(p[T[i]], p[0]);
        if (i < K - 1) { std::swap(p[T[i + 1] == 0 ? T[i] : T[i + 1]], p[N - 1]); }
        for (int j = 1; j < N; j++) { ans.push_back(p[j]); }
    }
    std::cout << ans.size() << std::endl;
    for (const int e : ans) { std::cout << e + 1 << " "; }
    std::cout << std::endl;
    return 0;
}


Measured memory_bytes: 256