/*
* * author: attacker
* * created: 08.02.2026 17:56:27
*/
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include "algo/debug.h"
#else
#define debug(...) 42
#endif
#define mt_rng mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
int main() {
ios_base::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
int n;
cin >> n;
vector<pair<int64_t, int64_t>> a(n);
for (auto& [w, v] : a) {
cin >> w >> v;
}
sort(a.begin(), a.end());
int64_t ans = 0;
for (int i = 0; i < n; i++) {
int64_t s = 0, mx = -1, mn = int64_t(1e18);
for (int j = i; j < n; j++) {
auto [w, v] = a[j];
s += v;
mx = max(mx, w);
mn = min(mn, w);
ans = max(ans, s - mx + mn);
}
}
cout << ans << '\n';
return 0;
}
