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
#include<bits/stdc++.h>
bool Mbg;
using namespace std;
#define vec vector
#define pb push_back
#define eb emplace_back
#define siz(vec) (int)((vec).size())
#define all(vec) (vec).begin(),(vec).end()
template<class T>
void operator +=(vec<T> &lhs,const T &rhs){lhs.push_back(rhs);}
#define pii pair<int,int>
#define x first
#define y second
#define mp make_pair
#define exc(expr) if(expr)continue;
#define stop(expr) if(expr)break;
#define ret(expr) if(expr)return;
#define deb(var) cerr<<#var<<'='<<(var)<<"; "
#define debl(var) cerr<<#var<<'='<<(var)<<";\n"
#define ins insert
#define era erase
#define lb lower_bound
#define ub upper_bound
#define int long long
#define inf (long long)(1e18)
template<class T>
bool Min(T &x,const T &y){return x>y?x=y,1:0;}
template<class T>
bool Max(T &x,const T &y){return x<y?x=y,1:0;}
const int mod=998244353;
void Add(int &x,const int &y){x=x+y<mod?x+y:x+y-mod;}
void Dec(int &x,const int &y){x=x>=y?x-y:x-y+mod;}
int fpm(int x,int y){
    int ans=1;for(;y;y>>=1,x=1ll*x*x%mod)if(y&1)ans=1ll*x*ans%mod;return ans;
}

int n,w,h[500010],c[500010],f[500010],g[500010];

pii opt;
void chk(int x){
    Max(opt,{f[x],x});
}
void work(){
    cin>>n>>w;
    for(int i=1;i<=n;i++){
        cin>>h[i]>>c[i];
    }

    opt={0,1};

    for(int i=1,j=1;i<=n;){
        while(j<=n&&h[j]==h[i]){
            g[j]=f[c[j]]+h[j];
            if(opt.y!=c[j]){
                Max(g[j],opt.x+h[i]-w);
            }
            ++j;
        }
        while(i<j){
            Max(f[c[i]],g[i]);
            Max(opt,{f[c[i]],c[i]});
            ++i;
        }
        
    }

    cout<<opt.x<<'\n';

}
bool Med;
signed main(){
    ios::sync_with_stdio(0),
    cin.tie(0),cout.tie(0);
    int T=1;while(T--)work();
    // cerr<<"Time: "<<clock()<<" ms;\n";
    // cerr<<"Memory: "<<abs(&Med-&Mbg)/1024.0/1024.0<<" MiB.\n";
}
/*
- CONTINUE, NON-STOPPING, FOR THE FAITH
- START TYPING IF YOU DON'T KNOW WHAT TO DO
- STOP TYPING IF YOU DON'T KNOW WHAT YOU'RE DOING
*/