N, V, C = map(int, input().split())

dp = [-1] * (V+1)
dp[0] = 0
# i : i 円購入した
# ときの満足度の最大値
for _ in range(N):
    v, w = map(int, input().split())
    # ひとつ購入(ボーナス値 C を加算)
    for i in reversed(range(V+1)):
        if i+v > V: continue
        if dp[i] == -1: continue
        dp[i+v] = max(dp[i+v], dp[i] + w + C)

    # 複数購入(ボーナスなし)
    for i in range(V):
        if i+v > V: break
        if dp[i] == -1: continue
        dp[i+v] = max(dp[i+v], dp[i] + w)

ans = max(dp)
print(ans)