N,V,C = map(int, input().split())
VW = [list(map(int, input().split())) for _ in range(N)]
if not (1<=N<=1000 and 1<=V<=5000 and 1<=C<=5000):
    exit()
for v,w in VW:
    if 1<=v<=5000 and 1<=w<=5000:
        continue
    exit()

DP = [0]*(V+1)
for v,w in VW:
    w+=C
    for i in reversed(range(V)):
        if DP[i]>0 and i+v<=V and DP[i+v]<DP[i]+w:
            DP[i+v]=DP[i]+w
    if v<=V and DP[v]<w:
        DP[v]=w
for v,w in VW:
    for i in range(V):
        if DP[i]>0 and i+v<=V and DP[i+v]<DP[i]+w:
            DP[i+v]=DP[i]+w
print(max(DP))