import sys
input = sys.stdin.buffer.readline
sys.setrecursionlimit(10 ** 7)
inf = 10 ** 10

N, V, C = map(int, input().split())
dp = [-inf] * (V + 1)
dp[0] = 0
for _ in range(N):
    v, w = map(int, input().split())
    ndp = [-inf] * (V + 1)
    for i in range(v, V + 1):
        ndp[i] = max(dp[i-v] + w, ndp[i-v] + w)
    for i in range(V+1):
        dp[i] = max(dp[i], ndp[i] + C)

print(max(dp))