#include<bits/stdc++.h>
namespace {
#pragma GCC diagnostic ignored "-Wunused-function"
#include<atcoder/all>
#pragma GCC diagnostic warning "-Wunused-function"
using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (int)(n); i++)
#define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--)
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; }
template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; }
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;
using mint = modint998244353;

} int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m, k;
  cin >> n >> m >> k;
  VI cnt(n + 1);
  rep(_, m) {
    int a;
    cin >> a;
    if (a <= n) cnt[a]++;
  }
  rrep(i, n + 1) if (i) {
    for (int j = i + i; j <= n; j += i) cnt[j] += cnt[i];
  }
  mint ans = n;
  mint minv = mint(m).inv();
  rrep(i, n + 1) if (i) {
    ans -= (1 - cnt[i] * minv).pow(k);
  }
  cout << ans.val() << '\n';
}