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.
from sys import stdin,stdout
from itertools import combinations
from collections import defaultdict,OrderedDict
import math
import heapq

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

def stringListIn():
    return([x for x in stdin.readline().split()])
    
def intIn():
    return (int(stdin.readline()))

def stringIn():
    return (stdin.readline().strip())


if __name__=="__main__":
    n,m=listIn()
    di=defaultdict(int)
    
    li=[]
    Arr=defaultdict(list)
    for i in range(m):
        a,b=listIn()
        li.append((a,b))
        Arr[a].append(i+1)
        Arr[b].append(i+1)
        di[a]+=1
        di[b]+=1
    
    a,b=li[0][0],li[0][1]
    li2=[]
    li2.append(a)
    li2.append(b)
    f=1
    for i in range(1,m):
        if a not in li[i] and b not in li[i]:
            f=0
            li2.append(li[i][0])
            li2.append(li[i][1])
            break
    
    #print(li2)
    if f:
        print('YES')
    else:
        f=0
        for i in [0,1]:
            s=set(Arr[li2[i]])
            for j in [2,3]:
                s1=s|set(Arr[li2[j]])
                if len(s1)==m:
                    #print(li2[i],li2[j])
                    f=1
                    break
            if f:
                break
        if f:
            print("YES")
        else:
            print('NO')