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

dp=[[-1]*(V+1) for i in range(N+1)]
dp[0][0] = 0

for i in range(N):
    v,w=map(int,input().split())
    for j in range(V+1):
        if dp[i][j] == -1:
            continue
        if j + v <= V:
            dp[i][j+v] = max(dp[i][j+v],dp[i][j] + w)
            dp[i+1][j+v] = max(dp[i][j] + w + C , dp[i+1][j+v])
        dp[i+1][j] = max(dp[i][j],dp[i+1][j]) 
        
print(max(dp[-1]))