• Mountain Climbing 동일한 문제. 풀이는 그쪽을 참고. 덤으로, Cakes도 동일한 문제.

"""Solution code for "BOJ 14778. The Milk Queue".

- Problem link: https://www.acmicpc.net/problem/14778
- Solution link: http://www.teferi.net/ps/problems/boj/14778

Tags: [greedy]
"""

import sys
import functools


def main():
    N = int(sys.stdin.readline())
    A_and_B = [[int(x) for x in sys.stdin.readline().split()] for _ in range(N)]

    A_and_B.sort(
        key=functools.cmp_to_key(
            lambda x, y: (
                (x[0] - x[1]) - (y[0] - y[1])
                if (comp := min(x[0], y[1]) - min(x[1], y[0])) == 0
                else comp
            )
        )
    )

    first_barn_time = second_barn_time = 0
    for a, b in A_and_B:
        first_barn_time += a
        second_barn_time = max(second_barn_time, first_barn_time) + b

    print(second_barn_time)


if __name__ == '__main__':
    main()