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

def cross3(a, b, c):
    return (b[0]-a[0])*(c[1]-a[1]) - (b[1]-a[1])*(c[0]-a[0])

def is_line(a, b, c):
    return cross3(a, b, c) == 0

# ps = [(x, y), ...]: ソートされた座標list
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)
    
    qs.pop()
    return qs

hull = convex_hull(points)

if len(hull) != N:
    print("No")
    exit()

for i in range(N):
    if is_line(hull[i], hull[(i+1)%N], hull[(i+2)%N]):
        print("No")
        exit()
print("Yes")