求条

lg 可过，这里全WA起初怀疑数据问题，后来发现有人已经过了/

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int maxn = 2e5 + 10;
int n;
struct Node {
	int a, b, id, fl;
	void build(int _a, int _b, int i) {
		a = _a, b = _b, id = i;
		if (a < b) fl = 1;
		if (a == b) fl = 0;
		if (a > b) fl = -1;
	}
} p[maxn];
bool cmp(Node x, Node y) {
	if (x.fl != y.fl) return x.fl > y.fl;
	else {
		if (x.fl >= 0) return x.a < y.a;
		else return x.b > y.b;
	}
}
signed main() {
	ios::sync_with_stdio(false);
	cin.tie(0), cout.tie(0);
	cin >> n;
	for (int i = 1, a, b; i <= n; i++) {
		cin >> a >> b;
		p[i].build(a, b, i);
	}
	sort(p + 1, p + n + 1, cmp);
	int ans = 0, sum = 0;
	for (int i = 1; i <= n; i++) {
		sum += p[i].a;
		ans = max(ans, sum) + p[i].b;
	}
	cout << ans;
	return 0;
}