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())
d={}
p=[]
for i in range(m):
	x,y=map(int,input().split())
	if x==y:
		d[x]=d.get(x,0)+1
	else:
		d[x]=d.get(x,0)+1
		d[y]=d.get(y,0)+1
	p.append([x,y])

xx=[]
# k=max(d.values())
x=0
for i in d:
	if d[i]>=m/2:
		xx.append(i)
# print(k,xx,len(xx))
if len(xx)==0:
	print('NO')
	exit()
y=0
for x in xx:
	p1=[]
	for i in p:
		if i[0]!=x and i[1]!=x:
			p1.append(i)
	# print(p1)

	d1={}
	for i in p1:
		if i[0]==i[1]:
			d1[i[0]]=d1.get(i[0],0)+1
		else:
			d1[i[0]]=d1.get(i[0],0)+1
			d1[i[1]]=d1.get(i[1],0)+1
	# print(d1,max(d1.values()))
	if len(d1)==0 or max(d1.values())==len(p1):
		y+=1
if y!=0:
	print('YES')
else:
	print('NO')