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

inf=float("inf")
DP=[-inf]*(V+1); DP[0]=0

for i in range(N):
    v,w=map(int,input().split())

    E=DP
    DP=[-inf]*(V+1)

    for j in range(V+1):
        if j<v:
            DP[j]=E[j]
        else:
            DP[j]=max(E[j],DP[j-v]+w,E[j-v]+w+C)

print(max(DP))