local mfl = math.floor
local function getpattern(n, patall, idx)
  local used = {}
  local retary = {}
  local div = patall
  for i = 1, n do used[i] = false end
  for i = n, 1, -1 do
    div = mfl(div / i)
    local v_idx = mfl(idx / div)
    idx = idx % div
    local tmp_idx = 0
    for j = 1, n do
      if(not used[j]) then
        if(tmp_idx == v_idx) then
          table.insert(retary, j)
          used[j] = true
          break
        else
          tmp_idx = tmp_idx + 1
        end
      end
    end
  end
  return retary
end

local function isZouKado(x1, x2, x3)
  return x1 < x3 and (x2 - x1) * (x3 - x2) < 0
end

local d = {}
for i = 1, 7 do d[i] = io.read("*n") end
local found = false
for i = 0, 5039 do
  local pat = getpattern(7, 5040, i)
  local t = true
  for j = 1, 5 do
    if not isZouKado(d[pat[j]], d[pat[j + 1]], d[pat[j + 2]]) then
      t = false
      break
    end
  end
  if t then found = true break end
end
print(found and "YES" or "NO")