def solve(n, P):
	sum_b = 0

	aa = bb = 0
	for a, b in P:
		if a < b:
			aa += a
		elif a > b:
			bb += b
		else:
			if aa < bb:
				aa += a
			else:
				bb += b
		sum_b += b
	ma = max(aa, bb)

	dp = [0] * ma
	t = 1
	for a, b in P:
		for j in range(min(t, ma - a - 1), -1, -1):
			dp[j + a] = max(dp[j + a], dp[j] + b)
		t = max(t, min(t, ma - a - 1) + a)

	ans = ma
	for i in range(ma):
		ans = min(ans, max(i, sum_b - dp[i]))

	return ans


def main():
	n = int(input())

	P = [None] * n

	for i in range(n):
		P[i] = tuple(map(int, input().split()))

	ans = solve(n, P)

	print(ans)


if __name__ == '__main__':
	main()