1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
// clang-format off
#include<bits/stdc++.h>
using namespace std;
using LL=long long;
#define FOR(i,l,r) for(auto i=(l);i<=(r);++i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) int(x.size())
template<class A,class B>auto&operator<<(ostream&o,pair<A,B>p){return o<<"("<<p.first<<", "<<p.second<<")";}
template<class T>auto operator<<(ostream&o,T x)->decltype(x.end(),o){o<<"{";int i=0;for(auto e:x)o<<(", ")+2*!i++<<e;return o<<"}";}
#ifdef DEBUG
#define debug(X...)cerr<<"["#X"]: ",[](auto...$){((cerr<<$<<"; "),...)<<"\n";}(X)
#else
#define debug(...) {}
#endif
// clang-format on

class RTree
{
    int base = 1;
    vector<LL> data;

   public:
    RTree(int n)
    {
        while (base < n) base <<= 1;
        data.resize(base << 1);
    }
    void set_atp(int v, LL x)
    {
        for (v += base; v; v >>= 1) data[v] = max(data[v], x);
    }
    LL max_onr(int l, int r)
    {
        LL res = 0;
        for (l += base, r += base; l <= r; l >>= 1, r >>= 1) {
            if (l & 1) res = max(res, data[l++]);
            if (!(r & 1)) res = max(res, data[r--]);
        }
        return res;
    }
};

const int MAX_TYPES = 500000;
int
main()
{
    cin.tie(0)->sync_with_stdio(0);
    LL N, penalty;
    cin >> N >> penalty;
    vector<pair<int, int>> seq(N);
    for (auto& x : seq) cin >> x.first >> x.second;
    debug(seq);

    RTree tree(MAX_TYPES + 1);
    vector<pair<int, LL>> batch;
    REP (n, N) {
        const auto& [val, type] = seq[n];
        auto keep_type          = tree.max_onr(type, type) + val;
        auto change_type
          = max(tree.max_onr(1, type - 1), tree.max_onr(type + 1, MAX_TYPES))
            + val - penalty;
        batch.emplace_back(type, max(keep_type, change_type));

        // Apply batch
        if (n + 1 == N || seq[n + 1].first != seq[n].first) {
            for (const auto& b : batch) tree.set_atp(b.first, b.second);
            batch.clear();
        }
    }
    cout << tree.max_onr(1, MAX_TYPES) << "\n";
    return 0;
}