#include <bits/stdc++.h>
using namespace std;

#define rep(i,n) for(int i=0;i<n;++i)
#define rrep(i,n) for(int i=n-1;i>=0;i--)

int n;
pair<int, int> P[200];
int ans;
int aa, bb;
int rest[200];

void dfs(int i) {
	int ma = max(aa, bb);
	int mi = min(aa, bb);

	if (ma + (rest[i] - (ma - mi)) / 2 >= ans) return;

	if (i == n) {
		if (ans > ma) {
			ans = ma;
			// out(ans);
		}
		return;
	}

	// i を A が
	aa += P[i].first;
	dfs(i+1);
	aa -= P[i].first;

	// i を B が
	bb += P[i].second;
	dfs(i+1);
	bb -= P[i].second;
}

int solve() {
	{
		int aa = 0, bb = 0;
		rep(i, n) {
			if (P[i].first < P[i].second) aa += P[i].first;
			else bb += P[i].second;
		}
		ans = max(aa, bb);
	}

	auto cmp = [&](pair<int, int> lhs, decltype(lhs) rhs) -> bool {
		return lhs.first + lhs.second > rhs.first + rhs.second;
	};
	sort(P, P+n, cmp);

	rrep(i, n-1) {
		rest[i] = rest[i+1] + min(P[i+1].first, P[i+1].second);
	}

	dfs(0);

	return ans;
}

int main() {
	cin.tie(nullptr);
	ios::sync_with_stdio(false);

	cin >> n;

	rep(i, n) {
		cin >> P[i].first >> P[i].second;
	}

	int ans = solve();

	cout << ans << endl;

	return 0;
}