Toad Ivan has m pairs of integers, each integer is between 1 and n, inclusive. The pairs are (a_1, b_1), (a_2, b_2), …, (a_m, b_m). 

He asks you to check if there exist two integers x and y (1 ≤ x < y ≤ n) such that in each given pair at least one integer is equal to x or y.

Input

The first line contains two space-separated integers n and m (2 ≤ n ≤ 300 000, 1 ≤ m ≤ 300 000) — the upper bound on the values of integers in the pairs, and the number of given pairs.

The next m lines contain two integers each, the i-th of them contains two space-separated integers a_i and b_i (1 ≤ a_i, b_i ≤ n, a_i ≠ b_i) — the integers in the i-th pair.

Output

Output "YES" if there exist two integers x and y (1 ≤ x < y ≤ n) such that in each given pair at least one integer is equal to x or y. Otherwise, print "NO". You can print each letter in any case (upper or lower).

Examples

Input


4 6
1 2
1 3
1 4
2 3
2 4
3 4


Output


NO


Input


5 4
1 2
2 3
3 4
4 5


Output


YES


Input


300000 5
1 2
1 2
1 2
1 2
1 2


Output


YES

Note

In the first example, you can't choose any x, y because for each such pair you can find a given pair where both numbers are different from chosen integers.

In the second example, you can choose x=2 and y=4.

In the third example, you can choose x=1 and y=2.
n , m = map(int , input().split())
a = []
b = []
for i in range(m):
	x , y = map(int , input().split())
	a.append(x)
	b.append(y)

g = {}
ai = a[0]
bi = b[0]

#taking ai
counter  = 0
for i in range(m):
	if ai != a[i] and ai != b[i]:
		if a[i] in g:
			g[a[i]] += 1
		else:
			g[a[i]] = 1

		if b[i] in g:
			g[b[i]] += 1
		else:
			g[b[i]] = 1
	else:
		counter +=1

flag = False
if counter == m:
		flag = True
for i in g:
	if g[i] == (m -counter):
		flag = True
		break
# print(g , counter , flag)
if flag != True:
	g = {}
	counter = 0
	for i in range(m):
		if bi != a[i] and bi != b[i]:
			if a[i] in g:
				g[a[i]] += 1
			else:
				g[a[i]] = 1

			if b[i] in g:
				g[b[i]] += 1
			else:
				g[b[i]] = 1
		else:
			counter +=1
	for i in g:
		if g[i] == (m -counter):
			flag = True
			break
	# print(g ,counter)

if flag == True:
	print("YES")
else:
	print("NO")







