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
#include <bits/stdc++.h>
#define int long long
#define pii pair<int, int>
#define piii pair<pair<int,int>, int>
#define st first.first
#define nd first.second
#define rd second
#define For(i, l, r) for (int i = l; i <= r; i++)
#define Forcin(l, r, a)        \
  for (int i = l; i <= r; i++) \
    cin >> a[i];
#define Ford(i, l, r) for (int i = l; i >= r; i--)
#define ben(v) v.begin(), v.end()
#define LOCAL 0
#define LOCAL2 0
using namespace std;
 
const int M = 500005, inf=1e9;
int n, c, dp[M], a[M], w[M];
 
signed main()
{
    cin.tie(0)->sync_with_stdio();
    if (LOCAL)
        freopen("a.txt", "r", stdin);
    if (LOCAL2)
        freopen("local_out.txt", "w", stdout);
    int maxi=0, maxi_cur=0, a_cur=0;
    cin>>n>>c;
    vector <pii> dp_change;
    For(i, 1, n){
        int a, w;
        cin>>a>>w;
        if (a>a_cur){
            maxi=max(maxi_cur, maxi);
            a_cur=a;
            maxi_cur=0;
            for(auto [pos, val]:dp_change)
                dp[pos]=val;
            dp_change.clear();
        }
        int val=max(dp[w]+a, maxi-c+a);
        dp_change.push_back({w, val});
        //dp[w]=max(dp[w]+a, maxi-c+a);
        maxi_cur=max(val, maxi_cur);
    }
    maxi=max(maxi, maxi_cur);
    cout << maxi<<'\n';
}