import sys
import pypyjit
import itertools
import heapq
import math
from collections import deque, defaultdict, Counter
import string
import random

input = sys.stdin.readline
sys.setrecursionlimit(10 ** 6)
pypyjit.set_param('max_unroll_recursion=-1')


N, Pmax, C = map(int, input().split())
P = [tuple(map(int, input().split())) for _ in range(N)]

dp = [0 for _ in range(Pmax + 1)]
for i in range(N):
    price, value = P[i]
    value += C
    for j in range(Pmax + 1)[::-1]:
        if j - price < 0:
            break
        dp[j] = max(dp[j], dp[j - price] + value)
for i in range(N):
    price, value = P[i]
    for j in range(Pmax + 1):
        if j - price < 0:
            continue
        dp[j] = max(dp[j], dp[j - price] + value)
print(max(dp))