1 #include <bits/stdc++.h>
2 using namespace std;
3 #define _for(i,a,b) for(int i = (a);i < b;i ++)
4 #define _rep(i,a,b) for(int i = (a);i > b;i --)
5 #define INF 0x3f3f3f3f
6 #define pb push_back
7 #define maxn 1005390
8 typedef long long ll;
9 typedef pair<int,int> P;//first 是最短距离，second 是顶点编号
10 inline ll read()
11 {
12 ll ans = 0;
13 char ch = getchar(), last = ' ';
14 while(!isdigit(ch)) last = ch, ch = getchar();
15 while(isdigit(ch)) ans = (ans << 1) + (ans << 3) + ch - '0', ch = getchar();
16 if(last == '-') ans = -ans;
17 return ans;
18 }
19 inline void write(ll x)
20 {
21 if(x < 0) x = -x, putchar('-');
22 if(x >= 10) write(x / 10);
23 putchar(x % 10 + '0');
24 }
25 int N;
26 stack<ll> s;
27 ll in[maxn];
28 ll h[maxn],out[maxn];
29 int main()
30 {
31 N = read();
32 _for(i,1,N+1)
33 {
34 h[i] = read();
35 out[i] = read();
36 }
37 _for(i,1,N+1)
38 {
39 while(!s.empty() && h[s.top()] < h[i])
40 {
41 in[i] += out[s.top()];
42 s.pop();
43 }
44 if(!s.empty())
45 in[s.top()] += out[i];
46 s.push(i);
47 }
48 ll ans = 0;
49 _for(i,1,N+1)
50 ans = max(ans,in[i]);
51 write(ans);
52 return 0;
53 }
