n,m,q=map(int,input().split())
ab=[]
for i in range(n):
  a,b=map(int,input().split())
  ab.append([a,b])

dp=[0]*(1<<n)
for bit in range(1<<n):
  cost=0
  val=0
  for i in range(n):
    if (bit>>i)&1:
      cost+=ab[i][0]
      val+=ab[i][1]
  if cost<=m:
    dp[bit]=val
  for i in range(n):
    if (bit>>i)&1==0:
      dp[bit|(1<<i)]=max(dp[bit|(1<<i)],dp[bit])

mask=(1<<n)-1
ans=0
for bit in range(1<<n):
  cost=0
  val=0
  for i in range(n):
    if (bit>>i)&1:
      cost+=ab[i][0]
      val+=ab[i][1]
  if cost<=q:
    ans=max(ans,val+dp[bit^mask])

print(ans)