import sys

sys.setrecursionlimit(10**7)
def I(): return int(sys.stdin.readline().rstrip())
def MI(): return map(int,sys.stdin.readline().rstrip().split())
def LI(): return list(map(int,sys.stdin.readline().rstrip().split()))
def LI2(): return list(map(int,sys.stdin.readline().rstrip()))
def S(): return sys.stdin.readline().rstrip()
def LS(): return list(sys.stdin.readline().rstrip().split())
def LS2(): return list(sys.stdin.readline().rstrip())


N = I()
WS = [tuple(MI()) for _ in range(N)]
WS.sort()

inf = 10**18
dp = [[inf]*(N+1) for i in range(N+1)]
dp[0][0] = 0
for i in range(1,N+1):
    w,s = WS[i-1]
    for j in range(i+1):
        dp[i][j] = dp[i-1][j]
        if j >= 1 and s >= dp[i-1][j-1]:
            dp[i][j] = min(dp[i][j],dp[i-1][j-1]+w)

for j in range(N,-1,-1):
    if dp[-1][j] < inf:
        print(j)
        break