#include<bits/stdc++.h>

using namespace std;

#define ll long long

#define ls rt<<1,l,m

#define rs rt<<1|1,m+1,r

#define pb push_back

const int INF=0x3f3f3f3f;

const int N=;

int tree[*N],lazy[*N];

int dp[][N];

int now[N],pre[N],a[N];

int i;

void push_up(int rt)

{

    tree[rt]=max(tree[rt<<],tree[rt<<|]);

}

void push_down(int rt)

{

    tree[rt<<]+=lazy[rt];

    lazy[rt<<]+=lazy[rt];

    tree[rt<<|]+=lazy[rt];

    lazy[rt<<|]+=lazy[rt];

    lazy[rt]=;

}

void build(int rt,int l,int r)

{

    if(l==r)

    {

        tree[rt]=dp[i-][l];

        return ;

    }

    int m=(l+r)>>;

    build(ls);

    build(rs);

    push_up(rt);

}

void update(int p,int delta,int rt,int l,int r)

{

    if(l==r)

    {

        tree[rt]+=delta;

        return ;

    }

    int m=(l+r)>>;

    if(p<=m)update(p,delta,ls);

    else update(p,delta,rs);

    push_up(rt);

}

void Update(int L,int R,int delta,int rt,int l,int r)

{

    if(L<=l&&r<=R)

    {

        tree[rt]+=delta;

        lazy[rt]+=delta;

        return ;

    }

    if(lazy[rt])push_down(rt);

    int m=(l+r)>>;

    if(L<=m)Update(L,R,delta,ls);

    if(R>m)Update(L,R,delta,rs);

    push_up(rt);

}

int query(int L,int R,int rt,int l,int r)

{

    if(L<=l&&r<=R)return tree[rt];

    if(lazy[rt])push_down(rt);

    int m=(l+r)>>,ans=;

    if(L<=m)ans=max(ans,query(L,R,ls));

    if(R>m)ans=max(ans,query(L,R,rs));

    return ans;

}

int main()

{

    int n,k;

    while(~scanf("%d%d",&n,&k))

    {

        memset(now,,sizeof(now));

        for(int i=;i<=n;i++)

        {

            cin>>a[i];

            pre[i]=now[a[i]];

            now[a[i]]=i;

        }

        dp[][]=;

        for(i=;i<=k;i++)

        {

            memset(tree,,sizeof(tree));

            memset(lazy,,sizeof(lazy));

            build(,,n);

            for(int j=i;j<=n;j++)

            {

                Update(pre[j],j-,,,,n);

                dp[i][j]=query(i-,j-,,,n);

            }

        }

        cout<<dp[k][n]<<endl;

    }

    return ;

}