#pragma GCC target("avx2") #pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using namespace atcoder; typedef long long ll; #define rep(i, n) for (int i = 0; i < (int)(n); i++) #define repr(i, n) for (int i = (int)(n) - 1; i >= 0; i--) #define repk(i, k, n) for (int i = k; i < (int)(n); i++) #define all(v) v.begin(), v.end() #define mod1 1000000007 #define mod2 998244353 #define mod3 100000007 #define vi vector #define vs vector #define vc vector #define vl vector #define vb vector #define vvi vector> #define vvc vector> #define vvl vector> #define vvb vector> #define vvvi vector>> #define vvvl vector>> #define pii pair #define pil pair #define pli pair #define pll pair #define vpii vector> #define vpll vector> #define vvpii vector>> #define vvpll vector>> // using mint = modint998244353; template void debug(T e) { cerr << e << endl; } template void debug(vector &v) { rep(i, v.size()) { cerr << v[i] << " "; } cerr << endl; } template void debug(vector> &v) { rep(i, v.size()) { rep(j, v[i].size()) { cerr << v[i][j] << " "; } cerr << endl; } } template void debug(vector> &v) { rep(i, v.size()) { cerr << v[i].first << " " << v[i].second << endl; } } template void debug(set &st) { for (auto itr = st.begin(); itr != st.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(multiset &ms) { for (auto itr = ms.begin(); itr != ms.end(); itr++) { cerr << *itr << " "; } cerr << endl; } template void debug(map &mp) { for (auto itr = mp.begin(); itr != mp.end(); itr++) { cerr << itr->first << " " << itr->second << endl; } } void debug_out() { cerr << endl; } template void debug_out(Head H, Tail... T) { cerr << H << " "; debug_out(T...); } ll my_pow(ll x, ll n, ll mod) { //  繰り返し二乗法.x^nをmodで割った余り. ll ret; if (n == 0) { ret = 1; } else if (n % 2 == 1) { ret = (x * my_pow((x * x) % mod, n / 2, mod)) % mod; } else { ret = my_pow((x * x) % mod, n / 2, mod); } return ret; } ll inv(ll x, ll mod) { return my_pow(x, mod - 2, mod); } int main() { ll N, M, K; cin >> N >> M >> K; vector A(M); for (ll i = 0; i < M; i++) { cin >> A[i]; } vector num(1000001, 0); for (ll i = 0; i < M; i++) { num[A[i]]++; } // 感電するものを引くケースの数 vector norate(N + 1); for (ll i = 1; i <= 1000000; i++) { for (ll j = 1; j * i <= N; j++) { norate[j * i] += num[i]; } } // debug(norate); vector pow_k(M + 1); for (ll i = 0; i <= M; i++) { pow_k[i] = my_pow(i, K, mod2); } ll invval = inv(pow_k[M], mod2); ll ans = 0; for (ll i = 1; i <= N; i++) { ll rate = (pow_k[M] + mod2 - pow_k[M - norate[i]]) % mod2; // debug_out(i, rate); rate = (rate * invval) % mod2; ans += rate; ans %= mod2; } cout << ans << endl; }