N, A, B = map(int, input().split())
XY = [tuple(map(int, input().split())) for _ in range(N)]

# (個数, 攻撃)
# (-攻撃, -個数)
#dp = [[SortedList(key=lambda x: (-x[1], -x[0])) for _ in range(A + 1)] for _ in range(N)]
dp = [[[] for _ in range(A + 1)] for _ in range(N)]

dp[0][0].append((0, 0))
if XY[0][0] <= A:
    dp[0][XY[0][0]].append((1, XY[0][1]))

for i in range(1, N):
    for j in range(A+1):
        min_attack = 10**12
        dp[i-1][j].sort(key=lambda x: (-x[1], -x[0]))
        for a in dp[i-1][j]:
            if a[1]+XY[i][1] >= min_attack:
                continue
            min_attack = a[1]+XY[i][1]
            if j+XY[i][0] <= A:
                dp[i][j+XY[i][0]].append((a[0]+1, a[1]+XY[i][1]))
            dp[i][j].append(a)

ans = 0
for a in dp[-1]:
    if a and a[0][0] > ans:
        ans = a[0][0]
print(ans)