#include <bits/stdc++.h>
long long dx[4] = {0, -1, 0, 1};
long long dy[4] = {1, 0, -1, 0};
using namespace std;
class pa3 {
 public:
  long long x, y, z;
  pa3(long long x = 0, long long y = 0, long long z = 0) : x(x), y(y), z(z) {}
  bool operator<(const pa3 &p) const {
    if (x != p.x) return x < p.x;
    if (y != p.y) return y < p.y;
    return z < p.z;
  }
  bool operator>(const pa3 &p) const {
    if (x != p.x) return x > p.x;
    if (y != p.y) return y > p.y;
    return z > p.z;
  }
  bool operator==(const pa3 &p) const {
    return x == p.x && y == p.y && z == p.z;
  }
  bool operator!=(const pa3 &p) const {
    return !(x == p.x && y == p.y && z == p.z);
  }
};
class pa4 {
 public:
  long long x;
  long long y, z, w;
  pa4(long long x = 0, long long y = 0, long long z = 0, long long w = 0)
      : x(x), y(y), z(z), w(w) {}
  bool operator<(const pa4 &p) const {
    if (x != p.x) return x < p.x;
    if (y != p.y) return y < p.y;
    if (z != p.z) return z < p.z;
    return w < p.w;
  }
  bool operator>(const pa4 &p) const {
    if (x != p.x) return x > p.x;
    if (y != p.y) return y > p.y;
    if (z != p.z) return z > p.z;
    return w > p.w;
  }
  bool operator==(const pa4 &p) const {
    return x == p.x && y == p.y && z == p.z && w == p.w;
  }
  bool operator!=(const pa4 &p) const {
    return !(x == p.x && y == p.y && z == p.z && w == p.w);
  }
};
class pa2 {
 public:
  long long x, y;
  pa2(long long x = 0, long long y = 0) : x(x), y(y) {}
  pa2 operator+(pa2 p) { return pa2(x + p.x, y + p.y); }
  pa2 operator-(pa2 p) { return pa2(x - p.x, y - p.y); }
  bool operator<(const pa2 &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator>(const pa2 &p) const { return x != p.x ? x > p.x : y > p.y; }
  bool operator==(const pa2 &p) const {
    return abs(x - p.x) == 0 && abs(y - p.y) == 0;
  }
  bool operator!=(const pa2 &p) const {
    return !(abs(x - p.x) == 0 && abs(y - p.y) == 0);
  }
};
class Point {
 public:
  double x, y;
  Point(double x = 0, double y = 0) : x(x), y(y) {}
  Point operator+(Point p) { return Point(x + p.x, y + p.y); }
  Point operator-(Point p) { return Point(x - p.x, y - p.y); }
  Point operator*(double a) { return Point(x * a, y * a); }
  Point operator/(double a) { return Point(x / a, y / a); }
  double absv() { return sqrt(norm()); }
  double norm() { return x * x + y * y; }
  bool operator<(const Point &p) const { return x != p.x ? x < p.x : y < p.y; }
  bool operator==(const Point &p) const {
    return fabs(x - p.x) < (1e-10) && fabs(y - p.y) < (1e-10);
  }
};
struct Segment {
  Point p1, p2;
};
double dot(Point a, Point b) { return a.x * b.x + a.y * b.y; }
double cross(Point a, Point b) { return a.x * b.y - a.y * b.x; }
bool parareru(Point a, Point b, Point c, Point d) {
  return abs(cross(a - b, d - c)) < (1e-10);
}
double distance_ls_p(Point a, Point b, Point c) {
  if (dot(b - a, c - a) < (1e-10)) return (c - a).absv();
  if (dot(a - b, c - b) < (1e-10)) return (c - b).absv();
  return abs(cross(b - a, c - a)) / (b - a).absv();
}
bool is_intersected_ls(Segment a, Segment b) {
  if (a.p1 == b.p1 || a.p2 == b.p1 || a.p1 == b.p2 || a.p2 == b.p2)
    return false;
  if (parareru((a.p2), (a.p1), (a.p1), (b.p2)) &&
      parareru((a.p2), (a.p1), (a.p1), (b.p1))) {
    if (dot(a.p1 - b.p1, a.p1 - b.p2) < (1e-10)) return true;
    if (dot(a.p2 - b.p1, a.p2 - b.p2) < (1e-10)) return true;
    if (dot(a.p1 - b.p1, a.p2 - b.p1) < (1e-10)) return true;
    if (dot(a.p1 - b.p2, a.p2 - b.p2) < (1e-10)) return true;
    return false;
  } else
    return (cross(a.p2 - a.p1, b.p1 - a.p1) * cross(a.p2 - a.p1, b.p2 - a.p1) <
            (1e-10)) &&
           (cross(b.p2 - b.p1, a.p1 - b.p1) * cross(b.p2 - b.p1, a.p2 - b.p1) <
            (1e-10));
}
double segment_dis(Segment a, Segment b) {
  if (is_intersected_ls(a, b)) return 0;
  double r = distance_ls_p(a.p1, a.p2, b.p1);
  r = min(r, distance_ls_p(a.p1, a.p2, b.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p2));
  r = min(r, distance_ls_p(b.p1, b.p2, a.p1));
  return r;
}
Point intersection_ls(Segment a, Segment b) {
  Point ba = b.p2 - b.p1;
  double d1 = abs(cross(ba, a.p1 - b.p1));
  double d2 = abs(cross(ba, a.p2 - b.p1));
  double t = d1 / (d1 + d2);
  return a.p1 + (a.p2 - a.p1) * t;
}
string itos(long long i) {
  ostringstream s;
  s << i;
  return s.str();
}
long long gcd(long long v, long long b) {
  if (v > b) return gcd(b, v);
  if (v == b) return b;
  if (b % v == 0) return v;
  return gcd(v, b % v);
}
double distans(double x1, double y1, double x2, double y2) {
  double rr = (x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2);
  return sqrt(rr);
}
long long mod;
long long pr[201000];
long long inv[201000];
long long beki(long long wa, long long rr, long long warukazu) {
  if (rr == 0) return 1 % warukazu;
  if (rr == 1) return wa % warukazu;
  if (rr % 2 == 1) return (beki(wa, rr - 1, warukazu) * wa) % warukazu;
  long long zx = beki(wa, rr / 2, warukazu);
  return (zx * zx) % warukazu;
}
pair<long long, long long> dp[1010][7000];
pair<long long, long long> dp2[1010][7000];
pair<long long, long long> mm = make_pair(1000000007, 1000000007);
long long a[1010], aa[1010];
vector<long long> yaku;
map<long long, long long> ma;
vector<pair<long long, long long> > ans;
signed main() {
  for (long long i = 0; i < 1010; i++)
    for (long long j = 0; j < 7000; j++) dp[i][j] = mm;
  dp[0][0] = make_pair(0, 0);
  long long n, k;
  scanf("%I64d%I64d", &n, &k);
  for (long long i = 0; i < n; i++) {
    scanf("%I64d", &a[i]);
    aa[i] = gcd(a[i], k);
  }
  if (k == 1) {
    cout << 1 << endl;
    long long dai = 1000000007 * 1000000000ll;
    long long it;
    for (long long i = 0; i < n; i++) {
      if (dai > a[i]) {
        it = i;
        dai = a[i];
      }
    }
    cout << it + 1 << endl;
    return 0;
  }
  yaku.push_back(1);
  for (long long i = 2; i * i <= k; i++)
    if (k % i == 0) {
      if (i * i == k)
        yaku.push_back(i);
      else {
        yaku.push_back(i);
        yaku.push_back(k / i);
      }
    }
  yaku.push_back(k);
  long long d = yaku.size();
  for (long long i = 0; i < d; i++) {
    ma[yaku[i]] = i;
  }
  for (long long i = 0; i < n; i++)
    for (long long j = 0; j < d; j++) {
      if (dp[i][j] == mm) continue;
      if (dp[i + 1][j] > dp[i][j]) {
        dp[i + 1][j] = dp[i][j];
        dp2[i + 1][j] = make_pair(i, j);
      }
      pair<long long, long long> z =
          make_pair(dp[i][j].first + 1, dp[i][j].second + a[i]);
      long long f = ma[gcd(k, yaku[j] * aa[i])];
      if (dp[i + 1][f] > z) {
        dp[i + 1][f] = z;
        dp2[i + 1][f] = make_pair(i, j);
      }
    }
  if (dp[n][d - 1] == mm) {
    cout << -1 << endl;
    return 0;
  }
  cout << dp[n][d - 1].first << endl;
  pair<long long, long long> zz = make_pair(n, d - 1);
  while (1) {
    ans.push_back(dp[zz.first][zz.second]);
    if (zz.first == 0) break;
    zz = dp2[zz.first][zz.second];
  }
  reverse(ans.begin(), ans.end());
  for (long long i = 0; i < n; i++)
    if (ans[i + 1].first > ans[i].first) printf("%I64d ", i + 1);
  printf("\n");
  return 0;
}
