#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--)

struct xor128_random {
	uint32_t seed;
	random_device rnd;
	xor128_random(uint32_t s = 0) {
		if (s) seed = s;
		else seed = (uint32_t) rnd();
		for (int i = 0; i < 10; ++i) next();
	}

	uint32_t next() {
		static uint32_t x = 123456789, y = 362436069, z = 521288629, w = seed;
		uint32_t t = x ^ (x << 11);
		x = y;
		y = z;
		z = w;
		w = (w ^ (w >> 19)) ^ (t ^ (t >> 8));
		return w;
	}

	uint32_t operator()() { return next(); }
};
xor128_random rnd;

int yamanobori(const int n, const vector<int> &A, const vector<int> &B) {
	int bb = accumulate(B.begin(), B.end(), 0);

	vector<tuple<double, int, int>> problems;
	rep(i, n) {
		problems.emplace_back(1.0 * A[i] / B[i], A[i], B[i]);
	}

	sort(problems.begin(), problems.end());

	int ans = bb;

	int aa = 0;
	int idx = 0;
	int grea = 0, greb = bb;

	rep(i, n) {
		aa += get<1>(problems[i]);
		bb -= get<2>(problems[i]);
		if (max(aa, bb) < ans) {
			idx = i;
			grea = aa;
			greb = bb;
			ans = max(aa, bb);
		}
	}

	rep(_, 500) {
		int cura = grea;
		int curb = greb;

		vector<bool> X(n, 1);
		rep(i, idx+1) X[i] = 0;

		rep(t, 100000) {
			int i = rnd() % n;

			int nexa = cura, nexb = curb;
			if (X[i]) {
				// b to a
				nexa += get<1>(problems[i]);
				nexb -= get<2>(problems[i]);
			}
			else {
				// a to b
				nexa -= get<1>(problems[i]);
				nexb += get<2>(problems[i]);
			}

			if (max(nexa, nexb) < max(cura, curb)) {
				X[i] = 1 - X[i];
				cura = nexa;
				curb = nexb;
				// out(t, cura, curb, max(cura, curb));
			}
		}

		// out(_, cura, curb, max(cura, curb));
		ans = min(ans, max(cura, curb));
	}
	return ans;
}

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

	int n;
	cin >> n;

	vector<int> A(n), B(n);
	rep(i, n) {
		cin >> A[i] >> B[i];
	}

	int ans = yamanobori(n, A, B);

	cout << ans << endl;

	return 0;
}