def solve(n, A, B):
	sum_b = 0

	aa = bb = 0
	for i in range(n):
		if aa < bb:
			aa += A[i]
		else:
			bb += B[i]
		sum_b += B[i]
	ma = max(aa, bb)

	dp = [0] * ma
	for i in range(n):
		a = A[i]
		b = B[i]
		for j in range(ma - a - 1, -1, -1):
			if dp[j + a] < dp[j] + b:
				dp[j + a] = dp[j] + b

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

	return ans


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

	A = [0] * n
	B = [0] * n

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

	ans = solve(n, A, B)

	print(ans)


if __name__ == '__main__':
	main()