#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const ll N=1e5+1e4;
map<ll,ll>Map,m;
ll t,n,k,cnt;
ll a[N],last[N],ha[N];
void Add(ll x)
{
    ha[m[x]]++;
    if(ha[m[x]]==1)cnt++;
}
void Del(ll x)
{
    ha[m[x]]--;
    if(ha[m[x]]==0)cnt--;
}
signed main()
{
    cin>>n>>k;
    for(ll i=1;i<=n;i++)
    {
        cin>>a[i];
        if(m[a[i]]==0)m[a[i]]=++t;
        last[i]=Map[a[i]];
        Map[a[i]]=i;
    }
    ll l=1;
    ll ans=0;
    for(int i=1;i<=n;i++)
    {
        Add(a[i]);
        while(cnt-1>k)
        {
            Del(a[l]);
            l++;
        }
        ans=max(ans,ha[m[a[i]]]);
    }
    cout<<ans;
    return 0;
}