inf=10**18
dxy=[(0,1), (1,0), (-1, 0), (0, -1)]
mod=10**9+7
MOD=998244353

N, V, C = map(int, input().split())
dp = [0]*(V+1)
fvw = []
VW = []
for _ in range(N):
    v, w = map(int, input().split())
    fvw.append([v, w+C])
    VW.append([v, w])

for i in range(N):
    v, w = fvw[i]
    for p in range(v, V+1)[::-1]: 
        dp[p] = max(dp[p], dp[p-v]+w)
for i in range(N):
    v, w = VW[i]
    for p in range(V+1):
        if p+v<V+1: dp[p+v] = max(dp[p+v], dp[p]+w)
print(max(dp))