N=int(input())
A=[]
for i in range(N):
  x,y=map(int, input().split())
  A.append((x,y))
  
A=sorted(A,key=lambda x: x[1])  
A=sorted(A,key=lambda x: x[0])  
def cross3(a, b, c):
    return (b[0]-a[0])*(c[1]-a[1]) - (b[1]-a[1])*(c[0]-a[0])


def convex_hull(ps):
    qs = []
    N = len(ps)
    for p in ps:
        # 一直線上で高々2点にする場合は ">=" にする
        while len(qs) > 1 and cross3(qs[-1], qs[-2], p) >= 0:
            qs.pop()
        qs.append(p)
    t = len(qs)
    for i in range(N-2, -1, -1):
        p = ps[i]
        while len(qs) > t and cross3(qs[-1], qs[-2], p) >= 0:
            qs.pop()
        qs.append(p)
    return qs

ans= convex_hull(A)
if len(ans)==N+1:
  print('Yes')
else:
  print('No')