#include<iostream>
#include<stack>
#define IO ios::sync_with_stdio(0);cin.tie(0);cout.tie(0)
#define int long long
using namespace std;
int n,h[50005],v[50005],s[50005],maxx=-1;
stack<int> st;
signed main(){
    IO;
    cin>>n;
    for(int i=1;i<=n;i++){
        cin>>h[i]>>v[i];
        //左边
        while(!st.empty()&&h[st.top()]<=h[i]) st.pop();
        if(!st.empty()) s[st.top()]+=v[i];
        st.push(i);
    }while(!st.empty()) st.pop();for(int i=n;i>=1;i--){
        //右边
        while(!st.empty()&&h[st.top()]<=h[i]) st.pop();
        if(!st.empty()) s[st.top()]+=v[i];
        st.push(i);
    }for(int i=1;i<=n;i++) maxx=max(maxx,s[i]);
    cout<<maxx;
    return 0;
}