#include <bits/stdc++.h>
#include <atcoder/all>
#define For(i, a, b) for(int i = a; i < b; i++)
#define rep(i, n) For(i, 0, n)
#define rFor(i, a, b) for(int i = a; i >= b; i--)
#define ALL(v) (v).begin(), (v).end()
#define rALL(v) (v).rbegin(), (v).rend()
using namespace std;

using lint = long long;
using ld = long double;
using mint = atcoder::modint998244353;

int INF = 2000000000;
lint LINF = 1000000000000000000;

int main() {
    int n, m, k;
    cin >> n >> m >> k;
    vector<int> a(m);
    rep(i, m) {
        cin >> a[i];
    }
    vector<int> cnt(n + 1, 0);
    for (int &x : a) {
        for (int y = x; y <= n; y += x) {
            cnt[y]++;
        }
    }
    mint ans = mint(0);
    For(i, 1, n + 1) {
        mint p = mint(mint(m - cnt[i]) / mint(m)).pow(k);
        p = mint(1) - p;
        ans += p;
    }
    cout << ans.val() << endl;
}