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())
arr=[list(map(int,input().split())) for i in range(m)]
a=arr[0][0]
b=arr[0][1]
arr1=[]
arr2=[]
for i in range(m):
    if a not in arr[i]:
        arr1.append(arr[i])
    if b not in arr[i]:
        arr2.append(arr[i])
try:
    s1=set(arr1[0])
    for i in arr1:
        s1=s1.intersection(set(i))
    s2=set(arr2[0])
    for i in arr2:
        s2=s2.intersection(set(i))
    s1=list(s1)
    s2=list(s2)
    #print(s1,s2)
    #print(arr1,arr2)
    if len(s1)>=1 or len(s2)>=1 or arr1==[] or arr2==[]:
        print("YES")
    else:
        print("NO")
except:
    print("YES")