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
73
74
75
76
77
78
79
80
81
82
83
84
85
86
#include <bits/stdc++.h>
using namespace std;

#ifdef DEBUG
auto &operator<<(auto &o, pair<auto, auto> p) {
    return o << "(" << p.first << ", " << p.second <<")";
}
auto operator<<(auto &o, auto x)-> decltype(x.end(), o) {
    o << "{";int i = 0;
    for(auto e : x) o << ", "+!i++<<e;
    return o <<"}";
}
#define debug(x...) cerr << "["#x"]: ",[](auto...$){((cerr<<$<<"; "),...)<<endl;}(x)
#else
#define debug(...) {}
#endif

#define int long long
#define all(x) x.begin(), x.end()
#define sz(x) (int)(x).size()
#define pb push_back
#define fi first
#define se second
typedef pair <int, int> pii;

constexpr int N = 5e5+7;

int A[N];
int C[N];
int BC[N];
vector <pii> prebuck[N];
vector <pii> buckets[N];
int worth[N];


void test() {
    debug("TC______________________");
    int n, c; cin>>n>>c;
    bool ok = true;
    for (int i=0; i<n; ++i) {
        cin>>A[i]>>C[i];
        if (i && A[i] == A[i-1]) {
            ok = false;
        }
    }

    int bmax = 0;
    if(ok) {
        for (int i=0; i<n; ++i) {
            BC[C[i]] = max(BC[C[i]] + A[i], bmax + A[i] - c);
            bmax = max(BC[C[i]], bmax);
        }
    }
    else {
        for (int i=0; i<n; ++i) {
            prebuck[A[i]].push_back({A[i], C[i]});
        }
        
        for (int i=1; i<N; ++i) {
            if (sz(prebuck[i]) == 0) continue;
            debug(i, "-------");
            sort(all(prebuck[i]));
            prebuck[i].erase(unique(all(prebuck[i])), prebuck[i].end());
            
            set <pii> best;
            for (auto &[s, col] : prebuck[i]) {
                int uu = max(BC[col] + s, bmax + s - c);
                best.insert({uu, col});
            }

            for (auto &[s, col] : best) {
                BC[col] = max(BC[col], s);
                bmax = max(BC[col], bmax);
            }
        }
    }
    cout<<bmax<<'\n';
}

signed main() {
  ios_base::sync_with_stdio(0); cin.tie(0);
  int t = 1; 
  while (t--) {
    test();
  }
}