#include <iostream>
#include <string>
#include <cmath>
#include<algorithm>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<iomanip>
#define _USE_MATH_DEFINES
#include <math.h>
#include <functional>
#include<complex>
#include<cassert>
using namespace std;

#define rep(i,x) for(ll i=0;i<x;i++)
#define repn(i,x) for(ll i=1;i<=x;i++)

typedef long long ll;
const ll INF = 1e17;
const ll MOD = 1000000007;
const ll MAX = 4000001;
const long double eps = 1E-14;

ll max(ll a, ll b) {
	if (a > b) { return a; }
	return b;
}

ll min(ll a, ll b) {
	if (a > b) { return b; }
	return a;
}

ll gcd(ll a, ll b) {
	if (b == 0) { return a; }
	if (a < b) { return gcd(b, a); }
	return gcd(b, a % b);
}

ll lcm(ll a, ll b) {
	return a / gcd(a, b) * b;
}

struct edge {
	ll ind;
	ll fr;
	ll to;
	ll d;
};

class mint {
	long long x;
public:
	mint(long long x = 0) : x((x% MOD + MOD) % MOD) {}
	mint operator-() const {
		return mint(-x);
	}
	mint& operator+=(const mint& a) {
		if ((x += a.x) >= MOD) x -= MOD;
		return *this;
	}
	mint& operator-=(const mint& a) {
		if ((x += MOD - a.x) >= MOD) x -= MOD;
		return *this;
	}
	mint& operator*=(const  mint& a) {
		(x *= a.x) %= MOD;
		return *this;
	}
	mint operator+(const mint& a) const {
		mint res(*this);
		return res += a;
	}
	mint operator-(const mint& a) const {
		mint res(*this);
		return res -= a;
	}
	mint operator*(const mint& a) const {
		mint res(*this);
		return res *= a;
	}

	mint pow(ll t) const {
		if (!t) return 1;
		mint a = pow(t >> 1);
		a *= a;
		if (t & 1) a *= *this;
		return a;
	}

	// for prime MOD
	mint inv() const {
		return pow(MOD - 2);
	}
	mint& operator/=(const mint& a) {
		return (*this) *= a.inv();
	}
	mint operator/(const mint& a) const {
		mint res(*this);
		return res /= a;
	}

	friend ostream& operator<<(ostream& os, const mint& m) {
		os << m.x;
		return os;
	}
};

mint pw(mint a, ll b) {
	if (b == 0) { return 1; }
	mint ret = pw(a, b >> 1);
	ret *= ret;
	if (b & 1) { ret *= a; }
	return ret;
}

typedef vector<ll> vll;
typedef vector<vector<ll>> vvll;
typedef vector<vector<vector<ll>>> vvvll;

typedef vector<mint> vmint;
typedef vector<vector<mint>> vvmint;
typedef vector<vector<vector<mint>>> vvvmint;

/////////////////////////////////////

int main(){
	ll N, K, M;
	cin >> N >> K >> M;

	vll A(M + 1);
	repn(i, M)cin >> A[i];

	repn(i, M-K+1) {
		vll col(K + 1, 0);
		repn(j, K) { col[A[i + j - 1]]++; }

		bool b = 1;
		repn(j, K) { if (col[j] == 0) { b = 0; break; } }
		if (b) {
			mint ans = pw(K, N - M) * (N - M + 1);
			cout << ans << endl;
			return 0;
		}
	}

	ll l = M;
	vll cnt(K + 1, 0);
	repn(i, M) {
		if (cnt[A[i]] == 1) { l = i-1; break; }
		cnt[A[i]] = 1;
	}

	ll r = M;
	cnt.assign(K + 1, 0);
	repn(i, M) {
		if (cnt[A[M + 1 - i]] == 1) { r = i - 1; break; }
		cnt[A[M+1-i]] = 1;
	}

	if (l<M) {
		//cout << l << " " << r << endl;

		vvmint dpl(N + 1, vmint(K, 0));
		vvmint rdpl(N + 1, vmint(K, 0));
		dpl[0][l] = 1;
		for (ll k = l; k < K; k++) { rdpl[0][k] = 1; }

		repn(i, N)repn(j, K-1) {
			dpl[i][j] = rdpl[i - 1][K - 1] - rdpl[i - 1][j - 1];
			dpl[i][j] += dpl[i - 1][j - 1] * (K - (j - 1));
			rdpl[i][j] = rdpl[i][j - 1] + dpl[i][j];
			//cout << i << " " << j << " " << dpl[i][j] << " " << rdpl[i][j] << endl;
		}

		vvmint dpr(N + 1, vmint(K, 0));
		vvmint rdpr(N + 1, vmint(K, 0));
		dpr[0][r] = 1;
		for (ll k = r; k < K; k++) { rdpr[0][k] = 1; }

		repn(i, N)repn(j, K-1) {
			dpr[i][j] = rdpr[i - 1][K - 1] - rdpr[i - 1][j - 1];
			dpr[i][j] += dpr[i - 1][j - 1] * (K - (j - 1));
			rdpr[i][j] = rdpr[i][j - 1] + dpr[i][j];			
		}

		mint ans = 0;
		rep(i, N - M + 1) {
			mint now = pw(K, N - M);
			now -= rdpl[i][K - 1] * rdpr[N - M - i][K - 1];

			//cout << i << " " << rdpr[i][K - 1] << endl;
			ans += now;
		}

		cout << ans << endl;
		return 0;
	}

	mint frac = 1;
	repn(i, M)frac *= (K - i + 1);

	vvmint dpl(N + 1, vmint(K, 0));
	vvmint rdpl(N + 1, vmint(K, 0));
	dpl[0][0] = (mint)1/frac;
	for (ll k = 0; k < K; k++) { rdpl[0][k] = (mint)1/frac; }

	repn(i, N)repn(j, K - 1) {
		dpl[i][j] = rdpl[i - 1][K - 1] - rdpl[i - 1][j - 1];
		dpl[i][j] += dpl[i - 1][j - 1] * (K - (j - 1));
		rdpl[i][j] = rdpl[i][j - 1] + dpl[i][j];
		//cout << i << " " << j << " " << dpl[i][j] << " " << rdpl[i][j] << endl;
	}

	vvmint dpr(N + 1, vmint(K, 0));
	vvmint rdpr(N + 1, vmint(K, 0));
	
	

	repn(i, N)repn(j, K - 1) {
		if (j >= M)dpr[i][j] = dpl[i][j];
		dpr[i][j] += rdpr[i - 1][K - 1] - rdpr[i - 1][j - 1];
		dpr[i][j] += dpr[i - 1][j - 1] * (K - (j - 1));
		rdpr[i][j] = rdpr[i][j - 1] + dpr[i][j];

		//cout << i << " " << j <<" "<< dpr[i][j] << " " << rdpr[i][j] << endl;
	}

	mint ans = pw(K, N - M)*(N-M+1) - rdpr[N][K - 1];
	cout << ans << endl;
	
}


Measured memory_bytes: 319684