#!/usr/bin/ python3.8
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
from operator import itemgetter

N = int(readline())
m = map(int, read().split())
VT = sorted(zip(m, m), key=lambda x: sum(x))

dp = 1
for v, t in VT:
    x = dp & ((1 << t) - 1)
    dp |= x << v

print(dp.bit_length() - 1)