N = int(input())
points = [tuple(map(int,input().split())) for _ in range(N)]
points.sort()

from functools import cmp_to_key

def ccw(a,b,c):
  ax,ay = a
  bx,by = b
  cx,cy = c
  bx -= ax
  cx -= ax
  by -= ay
  cy -= ay
  crs = bx*cy-cx*by
  if crs > 0:return 1
  if crs < 0: return -1
  return 0

upper = []
for p in points:
  while len(upper) >= 2 and ccw(upper[-2], upper[-1], p) >= 0:
    upper.pop()
  upper.append(p)

lower = []
for p in points[::-1]:
  while len(lower) >= 2 and ccw(lower[-2], lower[-1], p) >= 0:
    lower.pop()
  lower.append(p)

upper.pop()
lower.pop()

if  len(upper) + len(lower) == N:
  print("Yes")
else:
  print("No")