local mmi, mma = math.min, math.max
local n, x = io.read("*n", "*n")
local l, r = 100, 0
for i = 1, n do
  local c = io.read("*n")
  l = mmi(l, c)
  r = mma(r, c)
end
local f = l <= x and x <= r
print(f and "Yes" or "No")