from math import atan2
N = int(input())
points = []
for _ in range(N):
    x,y = list(map(int,input().split()))
    points.append((x,y))

mid_x = sum([x for x,y in points])/N
mid_y = sum([y for x,y in points])/N

pointss = []
for i in range(N):
    x,y = points[i]
    x -= mid_x
    y -= mid_y
    pointss.append((atan2(y,x),x,y))
pointss.sort()

def check(x1,y1,x2,y2):
    return x1*y2 - y1*x2 <= 0

for i in range(N):
    _,x1,y1 = pointss[i]
    _,x2,y2 = pointss[(i+1)%N]
    _,x3,y3 = pointss[(i+2)%N]
    
    if(check(x2-x1,y2-y1,x3-x2,y3-y2)):
        print("No")
        exit()

print("Yes")