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.
iarr = list(map(int,input().split()))
n=iarr[0]
m=iarr[1]

arr = [0 for i in range(n+1)]
xar = [0 for i in range(m)]
yar = [0 for i in range(m)]
for i in range(m):
	iarr = list(map(int,input().split()))
	x=iarr[0]
	y=iarr[1]
	xar[i]=x
	yar[i]=y
	arr[x]+=1
	arr[y]+=1

flag=0
for x in range(1,n+1):
	fx = arr[x]
	# if fx==m:
	# 	flag=1
	# 	break
	if fx>=(m//2):
		#print(x)
		sfarr = [0 for i in range(n+1)]
		for j in range(m):
			if xar[j]!=x and yar[j]!=x:
				sfarr[xar[j]]+=1
				sfarr[yar[j]]+=1
		for j in range(1,n+1):
			if sfarr[j]==m-fx:
				flag=1
				break

if flag==1:
	print("YES")
else:
	print("NO")	




# arr.sort()
# flag = 0
# l = 1
# r = n
# while (l<r):
# 	cur = arr[l] + arr[r]
# 	if cur==m:
# 		flag=1
# 		break
# 	elif cur<n:
# 		l+=1
# 	else:
# 		r-=1
# if flag==1:
# 	print("YES")
# else:
# 	print("NO")				
			

