n = int(input())
ws = [list(map(int, input().split())) for i in range(n)]
ws.sort(key=lambda x: x[0] + x[1])
dp = [[10 ** 18] * (n + 1) for i in range(n + 1)]
dp[0][0] = 0
for i in range(1, n + 1):
    for j in range(n + 1):
        if j == 0: dp[i][j] = 0; continue
        if dp[i - 1][j - 1] > ws[i - 1][1]:
            dp[i][j] = dp[i - 1][j]
        else:
            dp[i][j] = min(dp[i - 1][j], dp[i - 1][j - 1] + ws[i - 1][0])
for i in range(1, n + 1)[::-1]:
    if dp[n][i] != 10 ** 18: exit(print(i))