#include <iostream> #include <queue> #include <bitset> #include <stack> #include <vector> #include <cstring> #include <cmath> #include <unordered_map> #include <map> #include <set> #include <algorithm> #include <iomanip> #define F first #define S second #define PB push_back #define PF push_front #define MP make_pair using namespace std; typedef long long ll; typedef long double ld; typedef pair<int,int> pii; typedef unsigned long long ull; const int maxn = 1e5 + 100; pair <ll, ll> p[maxn]; int main (){ ios_base::sync_with_stdio (false); int n; cin >> n; for (int i = 1; i <= n; i++) cin >> p[i].F >> p[i].S; sort (p + 1, p + n + 1); ll ans = 0, sum = 0; for (int i = 1; i <= n; i++) { sum += p[i].S; ans = max (ans, sum + p[1].F - p[i].F); } cout << ans << endl; }