#include <bits/stdc++.h>
using namespace std;
using lint = long long int;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template<typename T> istream& operator>>(istream &is, vector<T> &vec){ for (auto &v : vec) is >> v; return is; }
template<typename T> ostream& operator<<(ostream &os, const vector<T> &vec){ os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream& operator<<(ostream &os, const set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream& operator<<(ostream &os, const unordered_set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream& operator<<(ostream &os, const multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream& operator<<(ostream &os, const unordered_multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T1, typename T2> ostream& operator<<(ostream &os, const pair<T1, T2> &pa){ os << "(" << pa.first << "," << pa.second << ")"; return os; }
template<typename TK, typename TV> ostream& operator<<(ostream &os, const map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename TK, typename TV> ostream& operator<<(ostream &os, const unordered_map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename T> void ndarray(vector<T> &vec, int len) { vec.resize(len); }
template<typename T, typename... Args> void ndarray(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); }
template<typename T> void Max(T &m, const T q) { if (m < q) m = q; }
template<typename T> void Min(T &m, const T q) { if (m > q) m = q; }
template<typename T1, typename T2> pair<T1, T2> operator+(pair<T1, T2> &l, pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template<typename T1, typename T2> pair<T1, T2> operator-(pair<T1, T2> &l, pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl;

constexpr lint MOD = 1000000007;
int N, K, M;
vector<int> A;

bool is_colorful(const vector<int> &vec, int k)
{
    map<int, int> ma;
    REP(i, vec.size())
    {
        ma[vec[i]]++;
        if (i >= k)
        {
            ma[vec[i - k]]--;
            if (ma[vec[i - k]] == 0) ma.erase(vec[i - k]);
        }
        if (ma.size() == k) return true;
    }
    return false;
}

bool is_barabara(const vector<int> &vec)
{
    map<int, int> ma;
    for (auto v : vec) ma[v]++;
    for (auto pa : ma) if (pa.second > 1) return false;
    return true;
}

int find_dabu(const vector<int> &vec)
{
    set<int> se;
    for (auto v : vec)
    {
        if (se.count(v)) break;
        se.insert(v);
    }
    return se.size();
}

lint power(lint x, lint n, lint MOD)
{
    lint ans = 1;
    while (n>0)
    {
        if (n & 1) (ans *= x) %= MOD;
        (x *= x) %= MOD;
       n >>= 1;
    }
   return ans;
}

vector<lint> dp1step(const vector<lint> &dp)
{
    vector<lint> res(K + 1);
    lint accum = accumulate(dp.begin(), dp.end(), 0LL) % MOD;
    REP(i, K)
    {
        accum = (accum - dp[i] + MOD) % MOD;
        res[i + 1] = (accum + dp[i] * (K - i)) % MOD;
    }
    return res;
}



// Solve ax+by=gcd(a, b)
lint extgcd(lint a, lint b, lint &x, lint &y)
{
    lint d = a;
    if (b != 0) d = extgcd(b, a % b, y, x), y -= (a / b) * x;
    else x = 1, y = 0;
    return d;
}
// Calc a^(-1) (MOD m)
lint mod_inverse(lint a, lint m)
{
    lint x, y;
    extgcd(a, m, x, y);
    return (m + x % m) % m;
}

vector<lint> fac, facInv, inv;
void facInit(int nmax)
{
    fac = facInv = inv = vector<lint>(nmax + 1, 1);
    for (int i = 2; i <= nmax; i++)
    {
        fac[i] = fac[i-1] * i % MOD;
        inv[i] = MOD - inv[MOD%i] * (MOD/i) % MOD;
        facInv[i] = facInv[i-1] * inv[i] % MOD;
    }
}
lint nCr(int n, int r)
{
    if (n<r || r<0) return 0;
    return (fac[n] * facInv[r] % MOD) * facInv[n-r] % MOD;
}

vector<lint> solve(vector<lint> dp)
{
    vector<lint> ans;
    REP(i, N + 1)
    {
        ans.push_back(accumulate(dp.begin(), dp.end(), 0LL) % MOD);
        dp = dp1step(dp);
        dp[K] = 0;
    }
    return ans;
}

int main()
{
    cin >> N >> K >> M;
    A.resize(M);
    cin >> A;

    facInit(N + K);

    lint tot = power(K, N - M, MOD) * (N - M + 1) % MOD; // Aを含むやつ総数(重複含む)
    if (is_colorful(A, K)) cout << tot << endl;
    else if (is_barabara(A))
    {
        // M項がバラバラなやつを数える
        vector<lint> dp(K + 1);
        vector<lint> dp2(K + 1);
        dp[0] = 1;
        REP(i, N)
        {
            dp = dp1step(dp);
            dp2 = dp1step(dp2);
            dp[K] = dp2[K] = 0;
            FOR(m, M, K) (dp2[m] += dp[m]) %= MOD;
        }
        lint ans = accumulate(dp2.begin(), dp2.end(), 0LL) % MOD;
        cout << (tot - ans * fac[K - M] % MOD * facInv[K] % MOD + MOD) % MOD << endl;
    }
    else
    {
        vector<lint> dp1(K + 1), dp2(K + 1);
        dp1[find_dabu(A)] = 1;
        reverse(A.begin(), A.end());
        dp2[find_dabu(A)] = 1;
        vector<lint> vec1 = solve(dp1);
        vector<lint> vec2 = solve(dp2);
        REP(i, N - M + 1)
        {
            tot -= vec1[i] * vec2[N - M - i] % MOD;
            tot = (tot + MOD) % MOD;
        }
        cout << tot << endl;
    }
}


Measured memory_bytes: 1536