N, M, C = map(int, input().split())
VW = [list(map(int, input().split())) for _ in range(N)]

dp = [[-float('inf')] * (M+1) for _ in range(N+1)]
dp[0][0] = 0
for i in range(N):
    v, w = VW[i]
    for j in range(M+1):
        if j + v <= M:
            dp[i+1][j+v] = max(dp[i+1][j+v], dp[i+1][j] + w, dp[i][j] + w + C)
        dp[i+1][j] = max(dp[i+1][j], dp[i][j])
ans = max(dp[N])
print(ans)