local n = io.read("*n")
local t = {}
for i = 1, n do
  local a, b = io.read("*n", "*n")
  local c, d = io.read("*n", "*n")
  local i1 = (a - 1) * 9 + b
  local i2 = (c - 1) * 9 + d
  local found = false
  for k, v in pairs(t) do
    if v == i1 then
      found = true
      t[k] = i2
      break
    end
  end
  if not found then t[i1] = i2 end
end
local r = t[17] == 44 and t[27] == 35 and t[63] == 53
print(r and "YES" or "NO")