N, V, C = map(int, input().split())
VW = [list(map(int, input().split())) for _ in range(N)]
# dp[v][k]:=v円かけて最大の満足度k: 0 その品物は買ったことがない 1: 2個目以上
# dp[i+v][1] = max(dp[i+v][1],dp[i][1]+w,dp[i][0]+C+w)
# 全部回ったら dp[i][0] = max(dp[i][0],dp[i][1])
#             dp[i][1] = 0

dp = [[0, 0] for _ in range(V + 1)]
for v, w in VW:
    for i in range(V):
        if i + v <= V:
            dp[i + v][1] = max(dp[i + v][1], dp[i][1] + w, dp[i][0] + C + w)
    for i in range(V + 1):
        dp[i][0] = max(dp[i][0], dp[i][1])
        dp[i][1] = 0
ans = 0
for i in range(V + 1):
    ans = max(ans, dp[i][0])
print(ans)