#include using std::cin; using std::cout; const char endl = '\n'; const int N = 35005, K = 55; template class SegmentTree { private: struct node { int l, r; T m, d; node *lchild, *rchild; node(int _l = 0, int _r = 0) : l(_l), r(_r), m(0), d(0), lchild(nullptr), rchild(nullptr) {} ~node() { delete lchild; delete rchild; } void pushup() { m = 0; if (lchild) m = std::max(m, lchild->m); if (rchild) m = std::max(m, rchild->m); } void pushdown() { if (!d) return; lchild->d += d; rchild->d += d; lchild->m += d; rchild->m += d; d = 0; } }; void build(node *&u, int l, int r) { u = new node(l, r); if (l == r) return; int mid = l + r >> 1; build(u->lchild, l, mid); build(u->rchild, mid + 1, r); } void modify(node *u, int l, int r, T v) { if (l <= u->l && u->r <= r) { u->d += v; u->m += v; return; } u->pushdown(); int mid = u->l + u->r >> 1; if (l <= mid) modify(u->lchild, l, r, v); if (r > mid) modify(u->rchild, l, r, v); u->pushup(); } T query(node *u, int l, int r) { if (l <= u->l && u->r <= r) return u->m; u->pushdown(); int mid = u->l + u->r >> 1; T res = 0; if (l <= mid) res = std::max(res, query(u->lchild, l, r)); if (r > mid) res = std::max(res, query(u->rchild, l, r)); return res; } node *root; public: SegmentTree(int n) : root(nullptr) { build(root, 1, n); } void modify(int l, int r, T v) { modify(root, l, r, v); } T query(int l, int r) { return query(root, l, r); } }; int n, k, a[N], pre[N], pos[N], f[K][N]; int main() { std::ios::sync_with_stdio(false); cin.tie(nullptr); cin >> n >> k; for (int i = 1; i <= n; i++) { cin >> a[i]; pre[i] = pos[a[i]]; pos[a[i]] = i; } for (int i = 1; i <= k; i++) { SegmentTree tr(n); for (int j = 1; j <= n; j++) { tr.modify(j, j, f[i - 1][j - 1]); } for (int j = 1; j <= n; j++) { tr.modify(pre[j] + 1, j, 1); f[i][j] = tr.query(i, j); } } cout << f[k][n] << endl; return 0; }