X, Y = [0] * 5, [0] * 5
for i in range(5):
    X[i], Y[i] = map(int, input().split())

def f(i, j, k):
    xj = X[j] - X[i]
    yj = Y[j] - Y[i]
    xk = X[k] - X[i]
    yk = Y[k] - Y[i]
    return xj * yk - xk * yj


for a in range(5):
    for b in range(a + 1, 5):
        for c in range(5):
            if a == c or b == c:
                continue
            if f(a, b, c) == 0:
                print("NO")
                exit()

print("YES")