#include using namespace std; using ll = long long; #define rep(i, n) for (int i = 0; i < n; i++) #define all(v) v.begin(), v.end() template inline bool chmax(T& a, U b) { if (a < b) { a = b; return true; } return false; } template inline bool chmin(T& a, U b) { if (a > b) { a = b; return true; } return false; } constexpr int INF = 1000000000; constexpr ll llINF = 3000000000000000000; constexpr int mod = 1000000007; const ll half = (mod + 1) / 2; constexpr double eps = 1e-10; vector prime_list(int n) { vector v(n + 1), res; for (int i = n; i >= 2; i--) { for (int j = i; j <= n; j += i) v[j] = i; } for (int i = 2; i <= n; i++) { if (v[i] == i) res.push_back(i); } return res; } vector next_divisor(int n) { vector v(n + 1); for (int i = n; i >= 2; i--) { for (int j = i; j <= n; j += i) v[j] = i; } return v; } ll modpow(ll a, ll b, ll m = mod) { ll res = 1; while (b) { if (b & 1) { res *= a; res %= m; } a *= a; a %= m; b >>= 1; } return res; } vector inv, fact, factinv; void init_fact(int n) { inv.resize(n + 1); fact.resize(n + 1); factinv.resize(n + 1); inv[0] = 0; inv[1] = 1; fact[0] = 1; factinv[0] = 1; for (ll i = 1; i <= n; i++) { if (i >= 2) inv[i] = mod - ((mod / i) * inv[mod % i] % mod); fact[i] = (fact[i - 1] * i) % mod; factinv[i] = factinv[i - 1] * inv[i] % mod; } } ll modinv(ll a, ll m = mod) { // gcd(a,m) must be 1 ll b = m, u = 1, v = 0; while (b) { ll t = a / b; a -= t * b; swap(a, b); u -= t * v; swap(u, v); } u %= m; if (u < 0) u += m; return u; } ll comb(int a, int b) { if (a < b) return 0; if (a < 0) return 0; return fact[a] * factinv[a - b] % mod * factinv[b] % mod; } template struct Matrix { int n; vector> m; Matrix(int x) : Matrix(vector>(x, vector(x, 0))) {} Matrix(const vector>& a) { n = a.size(); m = a; } vector& operator[](int i) { return m[i]; } const vector& operator[](int i) const { return m[i]; } static Matrix identity(int x) { Matrix res(x); for (int i = 0; i < x; i++) res[i][i] = 1; return res; } Matrix operator+(const Matrix& a) const { Matrix x = (*this); return x += a; } Matrix operator*(const Matrix& a) const { Matrix x = (*this); return x *= a; } Matrix& operator+=(const Matrix& a) { Matrix res(n); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { res[i][j] = (m[i][j] + a[i][j]) % mod; } } m = res.m; return *this; } Matrix& operator*=(const Matrix& a) { Matrix res(n); for (int i = 0; i < n; i++) { for (int j = 0; j < n; j++) { for (int k = 0; k < n; k++) { res[i][j] += m[i][k] * a[k][j]; res[i][j] %= mod; } } } m = res.m; return *this; } Matrix pow(ll b) const { Matrix x = *this, res = identity(n); res[0][0] = 1; while (b) { if (b & 1) { res *= x; } x *= x; b >>= 1; } return res; } }; void solve() { ll l; int n, m; cin >> l >> n >> m; vector flag(n + 1); rep(i, m) { int k; cin >> k; flag[k] = true; } vector> v((n + 1) * (n + 1), vector((n + 1) * (n + 1))); vector> initial((n + 1) * (n + 1), vector((n + 1) * (n + 1))); for (int i = 1; i <= n; i++) { for (int j = 0; j <= i; j++) { for (int k = 1; k <= n; k++) { if (flag[i] && i == j && i != k) continue; int f = (i == k ? (j == i || j == 0 ? 0 : j + 1) : 1); v[i * (n + 1) + j][k * (n + 1) + f] = 1; } } } for (int i = 1; i <= n; i++) { initial[i * (n + 1) + 1][i * (n + 1) + 1] = 1; } Matrix mat = Matrix(initial) * Matrix(v).pow(l - 1); ll ans = modpow(n, l); for (int i = 1; i <= n; i++) { for (int j = 1; j <= n; j++) { for (int k = 0; k <= n; k++) { if (flag[j] && k == j) continue; ans += mod - mat[i * (n + 1) + 1][j * (n + 1) + k]; } } } cout << ans % mod << endl; } int main() { cin.tie(0); ios::sync_with_stdio(false); /*int t; cin >> t; while (t--)*/ solve(); }