#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define rep1(i,n) for(int i=1;i<=(int)(n);i++)
#define all(c) c.begin(),c.end()
#define pb push_back
#define fs first
#define sc second
#define show(x) cout << #x << " = " << (x) << endl
#define chmin(x,y) x=min(x,y)
#define chmax(x,y) x=max(x,y)
using namespace std;
template<class S,class T> ostream& operator<<(ostream& o,const pair<S,T> &p){return o<<"("<<p.fs<<","<<p.sc<<")";}
template<class T> ostream& operator<<(ostream& o,const vector<T> &vc){o<<"sz = "<<vc.size()<<endl<<"[";for(const T& v:vc) o<<v<<",";o<<"]";return o;}
template<unsigned int mod_>
struct ModInt{
	using uint = unsigned int;
	using ll = long long;
	using ull = unsigned long long;

	constexpr static uint mod = mod_;

	uint v;
	ModInt():v(0){}
	ModInt(ll v):v(normS(v%mod+mod)){}
	explicit operator bool() const {return v!=0;}
	static uint normS(const uint &x){return (x<mod)?x:x-mod;}		// [0 , 2*mod-1] -> [0 , mod-1]
	static ModInt make(const uint &x){ModInt m; m.v=x; return m;}
	ModInt operator+(const ModInt& b) const { return make(normS(v+b.v));}
	ModInt operator-(const ModInt& b) const { return make(normS(v+mod-b.v));}
	ModInt operator-() const { return make(normS(mod-v)); }
	ModInt operator*(const ModInt& b) const { return make((ull)v*b.v%mod);}
	ModInt operator/(const ModInt& b) const { return *this*b.inv();}
	ModInt& operator+=(const ModInt& b){ return *this=*this+b;}
	ModInt& operator-=(const ModInt& b){ return *this=*this-b;}
	ModInt& operator*=(const ModInt& b){ return *this=*this*b;}
	ModInt& operator/=(const ModInt& b){ return *this=*this/b;}
	ll extgcd(ll a,ll b,ll &x,ll &y) const{
		ll u[]={a,1,0},v[]={b,0,1};
		while(*v){
			ll t=*u/ *v;
			rep(i,3) swap(u[i]-=t*v[i],v[i]);
		}
		if(u[0]<0) rep(i,3) u[i]=-u[i];
		x=u[1],y=u[2];
		return u[0];
	}
	ModInt inv() const{
		ll x,y;
		extgcd(v,mod,x,y);
		return make(normS(x+mod));
	}
	bool operator==(const ModInt& b) const { return v==b.v;}
	bool operator!=(const ModInt& b) const { return v!=b.v;}
	friend istream& operator>>(istream &o,ModInt& x){
		ll tmp;
		o>>tmp;
		x=ModInt(tmp);
		return o;
	}
	friend ostream& operator<<(ostream &o,const ModInt& x){ return o<<x.v;}
};
using mint = ModInt<1000000007>;

int N,K,M;
vector<int> a;
vector<mint> calc1(){
	vector<mint> dp(K);
	{
		set<int> st;
		rep(i,M){
			if(st.count(a[M-1-i])){
				dp[i] = 1;
				break;
			}
			st.insert(a[M-1-i]);
		}
	}

	vector<mint> res(N-M+1);
	res[0] = 1;
	rep(i,N-M){
//		show(dp);
		vector<mint> dif(K+2);
		rep(k,K){
			dif[1] += dp[k];
			dif[k+1] -= dp[k];
			dif[k+1] += dp[k]*(K-k);
			dif[k+2] -= dp[k]*(K-k);
		}
		rep1(k,K-1){
			dp[k] = dp[k-1] + dif[k];
		}
		rep(k,K) res[i+1] += dp[k];
	}
	return res;
}
mint solve1(){	//non-unique
	vector<mint> x = calc1();
	reverse(all(a));
	vector<mint> y = calc1();
//	show(x);
//	show(y);
	mint ans = 0;
	mint Kex = 1;
	rep(i,N-M) Kex *= K;
	rep(i,N-M+1){
		int j = N-M-i;
		ans += Kex-x[i]*y[j];
	}
	return ans;
}
bool uniq(){
	set<int> st;
	rep(i,M) st.insert(a[i]);
	return (int)st.size() == M;
}
int oknum;
vector<int> cnt;
void ad(int c){
	if(cnt[c]==1) oknum--;
	cnt[c]++;
	if(cnt[c]==1) oknum++;
}
void er(int c){
	if(cnt[c]==1) oknum--;
	cnt[c]--;
	if(cnt[c]==1) oknum++;
}

bool hascolorful(){
	if(M<K) return 0;
	cnt.resize(K);
	rep(i,K) ad(a[i]);
	if(oknum==K) return 1;
	rep(i,M-K){
		ad(a[K+i]);
		er(a[i]);
		if(oknum==K) return 1;
	}
	return 0;
}
mint solve2(){
	vector<vector<mint>> dp(K,vector<mint>(2));
	dp[0][0] = 1;

	rep(i,N){
		vector<vector<mint>> dif(K+2,vector<mint>(2));
		rep(t,2){
			rep(k,K){
				dif[1][t] += dp[k][t];
				dif[k+1][t] -= dp[k][t];
				dif[k+1][t] += dp[k][t]*(K-k);
				dif[k+2][t] -= dp[k][t]*(K-k);
			}
			rep(k,K){
				dp[k][t] = (k==0?0:dp[k-1][t]) + dif[k][t];
			}
		}
		for(int k=M;k<K;k++) dp[k][1] += dp[k][0];
	}

	mint res = 0;
	rep(i,K) res += dp[i][1];
	rep(i,M) res /= K-i;

	mint Kex = 1;
	rep(i,N-M) Kex *= K;

	res = Kex*(N-M+1) - res;
	return res;
}

int main(){
	cin>>N>>K>>M;
	a.resize(M);
	rep(i,M){
		cin>>a[i];
		a[i]--;
	}
	if(hascolorful()){
		mint ans = N-M+1;
		rep(i,N-M) ans *= K;
		cout<<ans<<endl;
		return 0;
	}
	if(!uniq()) cout<<solve1()<<endl;
	else cout<<solve2()<<endl;
}


Measured memory_bytes: 384