#include<bits/stdc++.h>
using namespace std;


template <int mod>
struct ModInt {
  int val;
  int trim(int x) const { return x >= mod ? x - mod : x < 0 ? x + mod : x; }
  ModInt(int v = 0) : val(trim(v % mod)) {}
  ModInt(long long v) : val(trim(v % mod)) {}
  ModInt &operator=(int v) { return val = trim(v % mod), *this; }
  ModInt &operator=(const ModInt &oth) { return val = oth.val, *this; }
  ModInt operator+(const ModInt &oth) const { return trim(val + oth.val); }
  ModInt operator-(const ModInt &oth) const { return trim(val - oth.val); }
  ModInt operator*(const ModInt &oth) const {
    return 1LL * val * oth.val % mod;
  }
  ModInt operator/(const ModInt &oth) const {
    function<int(int, int, int, int)> modinv = [&](int a, int b, int x, int y) {
      if (b == 0) return trim(x);
      return modinv(b, a - a / b * b, y, x - a / b * y);
    };
    return *this * modinv(oth.val, mod, 1, 0);
  }
  bool operator==(const ModInt &oth) const { return val == oth.val; }
  ModInt operator-() const { return trim(mod - val); }
  template<typename T> ModInt pow(T pw) {
    bool sgn = false;
    if (pw < 0) pw = -pw, sgn = true;
    ModInt ans = 1;
    for (ModInt cur = val; pw; pw >>= 1, cur = cur * cur) {
      if (pw&1) ans = ans * cur;
    }
    return sgn ? ModInt(1) / ans : ans;
  }
};

template<typename T>
vector<T> operator-(vector<T> A, vector<T> B) {
  for (int i = 0; i < A.size(); ++i) A[i] = A[i] - B[i];
  return A;
}

template<typename T>
vector<T> operator*(vector<T> A, T mul) {
  for (int i = 0; i < A.size(); ++i) A[i] = A[i] * mul;
  return A;
}

template<typename T>
vector<T> operator/(vector<T> A, T mul) {
  for (int i = 0; i < A.size(); ++i) A[i] = A[i] / mul;
  return A;
}


template<typename T>
T det(vector<vector<T>> A) {
  int N = A.size();
  T ans{1};
  for (int r = 0; r < N; ++r) {
    if (A[r][r] == T{0}) return T{0};
    ans = ans * A[r][r];
    for (int pvt = r + 1; pvt < N; ++pvt) {
      A[pvt] = A[pvt] - A[r] * A[pvt][r] / A[r][r];
    }
  }
  return ans;
}

const int MOD = 998244353;


int main() {
  ios_base::sync_with_stdio(false); cin.tie(0);
  int T; cin >> T;

while (T--) {
  int n, m; long long k; cin >> n >> m >> k;
  int adj[50][50];
  for (int i = 0; i < n; ++i) for (int j = 0; j < n; ++j) {
    adj[i][j] = i == j ? n - 1 : -1;
  }
  while (m--) {
    int u, v; cin >> u >> v;
    --u, --v;
    adj[u][v] = adj[v][u] = 0;
    --adj[u][u], --adj[v][v];
  }
  vector<vector<ModInt<MOD>>> mtx;
  if (k == 1) {
    mtx.assign(n - 1, vector<ModInt<MOD>>(n - 1));
    for (int i = 0; i < n - 1; ++i) for (int j = 0; j < n - 1; ++j) {
      mtx[i][j] = adj[i][j];
    }
    cout << det(mtx).val << '\n';
  }
  else {
    mtx.assign(n, vector<ModInt<MOD>>(n));
    for (int i = 0; i < n; ++i) for (int j = 0; j < n; ++j) {
      mtx[i][j] = adj[i][j] + (i == j ? (k - 1) * n % MOD : 0);
    }
    cout << ((det(mtx)/ModInt<MOD>{(k - 1) * n % MOD}).pow(k) *
             ModInt<MOD>(1ll * n * k % MOD).pow(k - 2)).val << '\n';
  }
}

}