def Map():
  return list(map(int,input().split()))

N,M,Q = Map()
A,B = [0]*N,[0]*N
for i in range(N):
  A[i],B[i] = Map()

dp = [0 for i in range(1 << N)]

for j in range(1 << N):
  a,b = 0,0
  for i in range(N):
    if (j >> i) & 1:
      a += A[i]
      b += B[i]
  if a <= M:
    dp[j] = b

for j in range(1 << N):
  for i in range(N):
    if (j >> i) & 1:
      k = j ^ (1 << i)
      dp[j] = max(dp[j],dp[k])

ans = 0
mask = (1 << N) - 1
for j in range(1 << N):
  a,b = 0,0
  for i in range(N):
    if (j >> i) & 1:
      a += A[i]
      b += B[i]
  if a > Q:
    continue
  k = j ^ mask
  ans = max(ans,b + dp[k])
print(ans)