N, V, C = map(int, input().split())
VW = [tuple(map(int, input().split())) for _ in range(N)]
dp = [[-1] * (V + 1) for _ in range(N + 1)]
dp[0][0] = 0

def chmax(DP,i,v):
    if DP[i] < v: DP[i] = v
def chmin(DP,i,v):
    if DP[i] > v: DP[i] = v

# もらうDP
for i in range(1, N + 1): # dp表の行番号
    v, w = VW[i - 1]
    for j in range(V + 1):
        candi = -1
        # 上から ... dp[i - 1][j]
        x = dp[i - 1][j]
        if x != -1:
            candi = dp[i - 1][j]
        # 斜め上から ... dp[i - 1][j - v]
        if j - v >= 0:
            y = dp[i - 1][j - v]
            if y != -1:
                # 種類数が増える
                candi = max(candi, y + C + w)
        # 左から ... dp[i][j - v]
            z = dp[i][j - v]
            if z != -1:
                candi = max(candi, z + w)
        if candi != -1:
            dp[i][j] = candi

ans = max(dp[-1])
print(ans)