#include<iostream>

 #include<cstdio>

 #include<algorithm>

 #include<cmath>

 #include<cstring>

 #include<cstdlib>

 #include<set>

 #include<map>

 #include<vector>

 #include<stack>

 #include<queue>

 #define ll long long

 #define inf 2147383611

 #define MAXN 1001001

 using namespace std;

 inline ll read()

 {

     ll x=,f=;

     char ch;ch=getchar();

     while(!isdigit(ch)) {if(ch=='-') f=-;ch=getchar();}

     while(isdigit(ch)) {x=x*+ch-'';ch=getchar();}

     return x*f;

 }

 int n,a[MAXN],v[MAXN],st[MAXN],top,ans[MAXN],maxn;

 int main()

 {

     n=read();

     for(int i=;i<=n;i++) a[i]=read(),v[i]=read();

     for(int i=;i<=n;i++)

     {

         while(top&&a[st[top]]<=a[i]) top--;

         ans[st[top]]+=v[i];

         st[++top]=i;

     }

     top=;

     for(int i=n;i>=;i--)

     {

         while(top&&a[st[top]]<=a[i]) top--;

         ans[st[top]]+=v[i];

         st[++top]=i;

     }

     for(int i=;i<=n;i++) maxn=max(maxn,ans[i]);

     printf("%d",maxn);

 }