import sys

input = sys.stdin.buffer.readline

n, k, c = map(int, input().split())


# total limit = k としておく(文字がかぶる)

# dp: 重さiまでの最高価値としておく。


dp = [0] * (k + 1)

for _ in range(n):
    w, v = map(int, input().split())
    ndp = [0] * (k + 1)

    for i in range(k + 1):
        # dp[i]+c, ndp[i-v]とmxとればOK
        ndp[i] = max(ndp[i], dp[i])
        if i - w >= 0:
            ndp[i] = max(dp[i - w] + c + v, ndp[i])
            ndp[i] = max(ndp[i], ndp[i - w] + v)
    dp = ndp[:]
    # print("dp", dp)
print(max(dp))