// DP - Divide and Conqueor Optimization

#include <bits/stdc++.h>

using namespace std;

#define MAX 350005

int col[MAX];
int cnt[MAX], wh[MAX], tim = 0;
int after[MAX], pos[MAX];
int dp[MAX][55], n, k;
int ans = 0;

void calc(int part, int l, int r, int optl, int optr)
{
    if(l > r) return;
    int mid = (l+r)/2;
    int best = 0, opt = -1;
    ans = 0;
//    clr();
    //++tim, ans = 0;
    //range(min(mid-1, optr)+1, mid);
    for(int i=min(mid-1, optr)+1; i<=mid; i++){
        //if(wh[col[i]] != tim) wh[col[i]] = tim, cnt[col[i]] = 0;
        //if(cnt[col[i]] == 0) ans++;
        //cnt[col[i]]++;
        if(after[i] > mid) ans++;
    }
    for(int i=min(mid-1, optr); i>=optl; i--){
        int cur = dp[i][part-1] + ans;
        if(cur > best) best = cur, opt = i;
        //range(i, i);
        //if(wh[col[i]] != tim) wh[col[i]] = tim, cnt[col[i]] = 0;
        //if(cnt[col[i]] == 0) ans++;
        //cnt[col[i]]++;
        if(after[i] > mid) ans++;
    }
    if(opt == -1) return;
    dp[mid][part] = best;
    calc(part, l, mid-1, optl, opt);
    calc(part, mid+1, r, opt, optr);
}

int main()
{
    scanf("%d %d", &n, &k), k--;
    for(int i=1; i<=n; i++) scanf("%d", &col[i]);
    for(int i=1; i<=n; i++) pos[i] = n+1;
    for(int i=n; i>=1; i--){
        after[i] = pos[col[i]];
        pos[col[i]] = i;
    }
    ++tim, ans = 0;
    for(int i=1; i<=n; i++){
        if(wh[col[i]] != tim) wh[col[i]] = tim, cnt[col[i]] = 0;
        if(cnt[col[i]] == 0) ans++;
        cnt[col[i]]++;
        dp[i][0] = ans;
    }
    for(int i=1; i<=k; i++) calc(i, 0, n, 0, n);
    int ans = dp[n][k];
    cout << ans;
}