#include <iostream> #include <array> #include <algorithm> #define ll long long using namespace std; ll n, s, mx = -1e18, f = -1e18; array<ll,2> A[500000]; int main() { cin >> n; for (int i=0; i<n; ++i) { for (int j=0; j<2; ++j) { cin >> A[i][j]; } } sort(A, A+n); for (int i=0; i<n; ++i) { mx = max(mx, A[i][0]-s); s += A[i][1]; f = max(f, mx+s-A[i][0]); } cout << f << '\n'; }