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.
import sys,math

def read_int():
	return int(sys.stdin.readline().strip())

def read_int_list():
	return list(map(int,sys.stdin.readline().strip().split()))

def read_string():
	return sys.stdin.readline().strip()

def read_string_list(delim=" "):
	return sys.stdin.readline().strip().split(delim)


###### Author : Samir Vyas #######
###### Write Code Below    #######
n,m = read_int_list()

input_lists = []
for _ in range(m):
	input_lists.append(sorted(read_int_list()))

if m<=2:
	print("YES")
	sys.exit()

freqs = [0 for _ in range(n+1)]
first = input_lists[0][0]
for i in range(m):
	if first in input_lists[i]:
		freqs[first] += 1
	else:
		freqs[input_lists[i][0]] += 1
		freqs[input_lists[i][1]] += 1

for i in range(1,n):
	if i!=first and freqs[i]+freqs[first] == m:
		print("YES")
		sys.exit()


freqs = [0 for _ in range(n+1)]
first = input_lists[0][1]	#note the change here
for i in range(m):
	if first in input_lists[i]:
		freqs[first] += 1
	else:
		freqs[input_lists[i][0]] += 1
		freqs[input_lists[i][1]] += 1

for i in range(1,n):
	if i!=first and freqs[i]+freqs[first] == m:
		print("YES")
		sys.exit()

print("NO")