#include<set>
#include <unordered_set>
#include <unordered_map>
#include<map>
#include<list>
#include<iomanip>
#include<cmath>
#include<string>
#include<vector>
#include<queue>
#include<stack>
#include<complex>
#include<sstream>
#include<iostream>
#include<fstream>
#include<algorithm>
#include<numeric>
#include<utility>
#include<functional>
#include<stdio.h>
#include<assert.h>
#include<memory.h>
#include<bitset>
#include<math.h>
#include <string.h>
#include <strings.h>


#define f first
#define s second
#define mp make_pair
#define pb push_back
#define lp(i,a,n) for(int i=(a);i<=(int)(n);++i)
#define lpd(i,a,n) for(int i=(a);i>=(int)(n);--i)
#define clr(a,b) memset(a,b,sizeof a)
#define all(v) v.begin(),v.end()
#define println(a) cout <<(a) <<endl
#define sz(x) ((int)(x).size())
#define readi(x) scanf("%d",&x)
#define read2i(x,y) scanf("%d%d",&x,&y)
#define read3i(x,y,z) scanf("%d%d%d",&x,&y,&z)
#define readll(x) scanf("%I64d",&x)
#define mod 1000000007
#define eps 1e-10
#define infi  1000000000ll
#define infll 1000000000000000000ll


using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vll;
typedef set<int> si;
typedef unordered_set<int> usi;
typedef map<int,int> mii;
typedef map<ll,ll> mll;
typedef unordered_map<ll,ll> umll;

const int N = 500002;
int n,k,a[N],rep[N+2],tree[N+5];
ll dp[N],sum[N];

void update (int i,int val) {
    ++i;
    while (i < N+2)
        tree[i] += val , i += i&-i;
}

int getSum(int i) {
    ++i;
    int ret = 0;
    while (i > 0) ret += tree[i] , i -=i&-i;
    return ret;
}
int main(){
    scanf("%d%d",&n,&k);

    lp(i,1 , n) scanf("%d",&a[i]);

    if(!k) {
        lp(i, 1, n) if(!a[i]) {
            printf("0\n");
            return 0;
        }
    }

    dp[0] = sum[1] = 1;
    int j = 1;
    lp(i,1 , n) {
        if(++rep[min(N,a[i])] == 1)
            update(min(N, a[i]), 1);
        while(j <= n && getSum(min(k, N)) == k+1) {
            --rep[min(a[j],N)];
            if(!rep[min(a[j],N)]) update(min(a[j],N), -1);
            ++j;
        }

        dp[i] += (sum[i] - sum[j-1] + mod)%mod;
        sum[i+1] = (sum[i]+dp[i])%mod;
    }

    printf("%lld\n",dp[n]);
    return 0;
}

/*
 */

//ios::sync_with_stdio(0);cin.tie(0);