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 collections import defaultdict
from itertools import combinations 
from itertools import permutations  


class RestAPI(object):
    def __init__(self, n, m, pairs):  
        self.pairs = pairs[:] 
        self.n = n
        self.m = m 
        self.xy_cnt_dt = defaultdict(int)
        self.xy_dt = defaultdict(list)
        for i, (a, b) in enumerate(self.pairs):
            self.xy_cnt_dt[a] += 1
            self.xy_cnt_dt[b] += 1
            self.xy_dt[a] += [i] 
            self.xy_dt[b] += [i]
        self.xy_cnt_dt = sorted(self.xy_cnt_dt.items(), key=lambda x: x[1]) 

    def function(self):
        for i, (x, cnt_x) in reversed(list(enumerate(self.xy_cnt_dt))): 
            if cnt_x >= (self.m + 1) // 2:
                if cnt_x >= self.m - 1:
                    return "YES"        

                # for j, (y, cnt_y) in reversed(list(enumerate(self.xy_cnt_dt[:i]))):
                #     if cnt_x + cnt_y >= self.m:
                #         if len(set(self.xy_dt[x] + self.xy_dt[y])) == m:
                #             return "YES"
                #     else:
                #         break

                scnd = set()
                for j in set(range(self.m)) - set(self.xy_dt[x]):
                    lf, rt = self.pairs[j]
                    if not scnd:
                        scnd = set([lf, rt])
                    else:
                        scnd &= set([lf, rt]) 
                        if not scnd:
                            break
                if scnd:
                    return "YES"   
            else:
                return "NO"

        return "NO" 





if __name__ == '__main__':
    # unittest.main() 
    n, m = map(int, input().split())
    pairs = [tuple(map(int, input().split())) for _ in range(m)] 
    api = RestAPI(n, m, pairs)
    response = api.function()
    print(response)
