#include <bits/stdc++.h>

//#include <atcoder/all>
using namespace std;

#define lli long long int
#define REP(i, s, n) for (lli i = s; i < n; i++)
#define INF (1LL << 62)
#define mp(a, b) make_pair(a, b)
#define SORT(V) sort(V.begin(), V.end())
#define PI (3.141592653589794)
#define TO_STRING(VariableName) #VariableName
#define LOG1(x)                                                                \
  if (DEBUG)                                                                   \
    cout << TO_STRING(x) << "=" << x << " " << endl;
#define LOG2(x, y)                                                             \
  if (DEBUG)                                                                   \
    cout << TO_STRING(x) << "=" << x << " " << TO_STRING(y) << "=" << y << endl;
#define LOG3(x, y, z)                                                          \
  if (DEBUG)                                                                   \
    cout << TO_STRING(x) << "=" << x << " " << TO_STRING(y) << "=" << y << " " \
         << TO_STRING(z) << "=" << z << endl;
#define LOG4(w, x, y, z)                                                       \
  if (DEBUG)                                                                   \
    cout << TO_STRING(w) << "=" << w << " " << TO_STRING(x) << "=" << x << " " \
         << TO_STRING(y) << "=" << y << " " << TO_STRING(z) << "=" << z        \
         << endl;
#define LOG5(w, x, y, z, a)                                                    \
  if (DEBUG)                                                                   \
    cout << TO_STRING(w) << "=" << w << " " << TO_STRING(x) << "=" << x << " " \
         << TO_STRING(y) << "=" << y << " " << TO_STRING(z) << "=" << z << " " \
         << TO_STRING(a) << "=" << a << endl;
#define LOG6(w, x, y, z, a, b)                                                 \
  if (DEBUG)                                                                   \
    cout << TO_STRING(w) << "=" << w << " " << TO_STRING(x) << "=" << x << " " \
         << TO_STRING(y) << "=" << y << " " << TO_STRING(z) << "=" << z << " " \
         << TO_STRING(a) << "=" << a << " " << TO_STRING(b) << "=" << b        \
         << endl;

#define overload6(a, b, c, d, e, f, g, ...) g
#define LOG(...)                                                               \
  overload6(__VA_ARGS__, LOG6, LOG5, LOG4, LOG3, LOG2, LOG1)(__VA_ARGS__)

template <class T> bool chmax(T &a, const T &b) {
  if (a < b) {
    a = b;
    return 1;
  }
  return 0;
}
template <class T> bool chmin(T &a, const T &b) {
  if (b < a) {
    a = b;
    return 1;
  }
  return 0;
}

mt19937 engine;
std::chrono::system_clock::time_point start, endTime;

#define DEBUG 1

// modint: mod 計算を int を扱うように扱える構造体
template <int MOD> struct Fp {
  long long val;
  constexpr Fp(long long v = 0) noexcept : val(v % MOD) {
    if (val < 0)
      val += MOD;
  }
  constexpr int getmod() { return MOD; }
  constexpr Fp operator-() const noexcept { return val ? MOD - val : 0; }
  constexpr Fp operator+(const Fp &r) const noexcept { return Fp(*this) += r; }
  constexpr Fp operator-(const Fp &r) const noexcept { return Fp(*this) -= r; }
  constexpr Fp operator*(const Fp &r) const noexcept { return Fp(*this) *= r; }
  constexpr Fp operator/(const Fp &r) const noexcept { return Fp(*this) /= r; }
  constexpr Fp &operator+=(const Fp &r) noexcept {
    val += r.val;
    if (val >= MOD)
      val -= MOD;
    return *this;
  }
  constexpr Fp &operator-=(const Fp &r) noexcept {
    val -= r.val;
    if (val < 0)
      val += MOD;
    return *this;
  }
  constexpr Fp &operator*=(const Fp &r) noexcept {
    val = val * r.val % MOD;
    return *this;
  }
  constexpr Fp &operator/=(const Fp &r) noexcept {
    long long a = r.val, b = MOD, u = 1, v = 0;
    while (b) {
      long long t = a / b;
      a -= t * b;
      swap(a, b);
      u -= t * v;
      swap(u, v);
    }
    val = val * u % MOD;
    if (val < 0)
      val += MOD;
    return *this;
  }
  constexpr bool operator==(const Fp &r) const noexcept {
    return this->val == r.val;
  }
  constexpr bool operator!=(const Fp &r) const noexcept {
    return this->val != r.val;
  }
  friend constexpr ostream &operator<<(ostream &os, const Fp<MOD> &x) noexcept {
    return os << x.val;
  }
  friend constexpr Fp<MOD> modpow(const Fp<MOD> &a, long long n) noexcept {
    if (n == 0)
      return 1;
    auto t = modpow(a, n / 2);
    t = t * t;
    if (n & 1)
      t = t * a;
    return t;
  }
};

const int MOD = 998244353;
using mint = Fp<MOD>;

mint pSum[1000100];

void solve() {
  //  write your code here

  lli N, M, K;
  cin >> N >> M >> K;

  map<lli, lli> cnts;

  REP(i, 0, M) {
    lli a;
    cin >> a;
    cnts[a]++;
  }

  REP(i, 0, N + 1) { pSum[i] = 0; }

  for (auto e : cnts) {
    auto nowNum = e.first;
    auto nowCnt = e.second;
    for (int i = nowNum; i <= N; i += nowNum) {
      pSum[i] += nowCnt;
    }
  }
  mint ans = 0;
  REP(i, 1, N + 1) {
    mint p = pSum[i] / M;
    mint pp = (mint)1 - p;
    mint ppp = modpow(pp, K);

    ans += mint(1) - ppp;
  }

  cout << ans << endl;
}

// Generated by 2.13.0 https://github.com/kyuridenamida/atcoder-tools  (tips:
// You use the default template now. You can remove this line by using your
// custom template)
int main() {
  // Failed to predict input format

  lli N = 1;
  // cin >> N;
  while (N--)
    solve();

  return 0;
}