#t = int(input())
t = 1
def check(x):
  su = 0
  cur = 0
  for i in range(n):
    su = a[i]
    if su >= x:
      cur += i
      break
  su = 0
  for i in range(n-1,-1,-1):
    su = L-a[i]
    if su >= x:
      cur += (n-1-i)
      break
  if cur <= n-k:
    return True
  return False
for _ in range(t):
  n,L = map(int, input().split())
  k = int(input())
  a = list(map(int, input().split()))
  l = 0
  r = L
  while l+1< r:
    m = (l+r)//2
    if check(m):
      l = m
    else:
      r = m
  print(l)