#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace std;
using namespace __gnu_pbds;
 
#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define fbo find_by_order
#define ook order_of_key
 
typedef long long ll;
typedef pair<ll,ll> ii;
typedef vector<ll> vi;
typedef long double ld; 
typedef tree<int, null_type, less<int>, rb_tree_tag, tree_order_statistics_node_update> pbds;
typedef set<int>::iterator sit;
typedef map<int,int>::iterator mit;

int a[500001];
int L[500001];
const int MOD = 1e9 + 7;

ll mult(ll a, ll b)
{
	ll ans = (a*b)%MOD;
	if(ans<0) ans+=MOD;
	return ans;
}

ll add(ll a, ll b)
{
	a+=b;
	while(a>=MOD) a-=MOD;
	while(a<0) a+=MOD;
	return a;
}

ll dp[500001];
const int INF = int(1e7);
int cnt[500005];
int run;
int n,k; 

void add(int x)
{
	if(cnt[x]==0&&x<=k)
	{
		run++;
	}
	cnt[x]++;
}

void del(int x)
{
	if(cnt[x]==1&&x<=k)
	{
		run--;
	}
	cnt[x]--;
}

ll sum[500001];

ll S(int l, int r)
{
	if(l>r) return 0;
	if(l<0) return add(sum[r],1);
	else if(l==0) return sum[r];
	else return add(sum[r],MOD-sum[l-1]);
}

int main()
{
	ios_base::sync_with_stdio(0); cin.tie(0);
	cin>>n>>k;
	for(int i=0;i<n;i++)
	{
		cin>>a[i];
		a[i]=min(a[i],500001);
	}
	L[0]=0;
	if(k==0&&a[0]==0) L[0]=INF;
	int ptr=0;
	run=0;
	if(L[0]==0)
	{
		add(a[0]);
	}
	else
	{
		ptr=1;
	}
	for(int i=1;i<n;i++)
	{
		add(a[i]);
		while(run>=k+1&&ptr<i)
		{
			del(a[ptr]);
			ptr++;
		}
		if(ptr==i&&run>=k+1)
		{
			del(a[i]);
			ptr=i+1;
			L[i]=INF;
		}
		else
		{
			L[i]=ptr;
		}
	}
	if(L[0]==0) dp[0]=1;
	else dp[0]=0;
	sum[0]=dp[0];
	for(int i=1;i<n;i++)
	{
		dp[i]=S(L[i]-1,i-1);
		sum[i]=add(sum[i-1],dp[i]);
	}
	cout<<dp[n-1]<<'\n';
}