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
input = sys.stdin.readline
from operator import itemgetter

N, M = map(int, input().split())
A = [list(map(lambda x: int(x)-1, input().split())) for _ in range(M)]

B = [[] for _ in range(N)]
for i, (a1, a2) in enumerate(A):
    B[a1].append(i)
    B[a2].append(i)

def check(x1, x2):
    for a in A:
        if not x1 in a and not x2 in a:
            return False
    return True

C = []
for i in range(N):
    C.append((i, len(B[i])))

C.sort(reverse=True, key=itemgetter(1))
n1 = C[0][0]

ans = 'NO'
if len(B[n1]) == M:
    ans = "YES"
else:
    to_check = [True]*M
    for i in B[n1]:
        to_check[i] = False

    for m in range(M):
        if to_check[m]:
            a1, a2 = A[m]
            break

    if check(n1, a1):
        ans = "YES"
    if check(n1, a2):
        ans = "YES"
    
    i = B[n1][0]
    for k in A[i]:
        if k != n1:
            n2 = k

    to_check = [True]*M
    for i in B[n2]:
        to_check[i] = False

    for m in range(M):
        if to_check[m]:
            a1, a2 = A[m]
            break
    if check(n2, a1):
        ans = "YES"
    if check(n2, a2):
        ans = "YES"


print(ans)