Problem:
 Score : 500 points    Problem Statement Takahashi is not good at problems about trees in programming contests, and Aoki is helping him practice.  First, Takahashi created a tree with N vertices numbered 1 through N , and wrote 0 at each edge.  Then, Aoki gave him M queries. The i -th of them is as follows:   Increment the number written at each edge along the path connecting vertices a_i and b_i , by one.   After Takahashi executed all of the queries, he told Aoki that, for every edge, the written number became an even number.
However, Aoki forgot to confirm that the graph Takahashi created was actually a tree, and it is possible that Takahashi made a mistake in creating a tree or executing queries.  Determine whether there exists a tree that has the property mentioned by Takahashi.      Constraints  2 ≤ N ≤ 10^5  1 ≤ M ≤ 10^5  1 ≤ a_i,b_i ≤ N  a_i ≠ b_i         Input Input is given from Standard Input in the following format:  N  M  a_1  b_1 : a_M  b_M       Output Print YES if there exists a tree that has the property mentioned by Takahashi; print NO otherwise.        Sample Input 1 4 4
1 2
2 4
1 3
3 4      Sample Output 1 YES  For example, Takahashi's graph has the property mentioned by him if it has the following edges: 1-2 , 1-3 and 1-4 .
In this case, the number written at every edge will become 2 .       Sample Input 2 5 5
1 2
3 5
5 1
3 4
2 3      Sample Output 2 NO

Solution (Python):
n,m=map(int,input().split())
num=[0]*n
for i in range(m):
  a,b=map(int,input().split())
  a-=1;b-=1
  num[a]+=1;num[b]+=1
flag=0
for i in num:
  if i%2==1:
    flag=1
    break
if bool(flag):print("NO")
else:print("YES")

Solution (Python):
def main():
    N, M = map( int, input().split())
    AB = [ tuple( map( int, input().split())) for _ in range(M)]
    V = [0]*(N+1)
    for a, b in AB:
        V[a] += 1
        V[b] += 1
    for v in V:
        if v%2 == 1:
            print("NO")
            return
    print("YES")
        
if __name__ == '__main__':
    main()

Solution (Python):
import sys
def input(): return sys.stdin.readline().rstrip()
from collections import Counter
def main():
    n,m=map(int,input().split())
    AB=[]
    for i in range(m):
        a,b=map(int,input().split())
        AB.append(a)
        AB.append(b)
    abc=list(Counter(AB).values())
    print("YES" if all(x%2==0 for x in abc) else "NO")


if __name__=='__main__':
    main()

Solution (Python):
import sys
def input(): return sys.stdin.readline().rstrip()
from collections import Counter
def main():
    n,m=map(int,input().split())
    AB=[]
    for i in range(m):
        a,b=map(int,input().split())
        AB.append(a)
        AB.append(b)
    abc=list(Counter(AB).values())
    print("YES" if all(x%2==0 for x in abc) else "NO")


if __name__=='__main__':
    main()

Solution (Python):
n,m=map(int,input().split())
A=[0]*n
for i in range(m):
  a,b=map(int,input().split())
  A[a-1]+=1
  A[b-1]+=1
f=0
for i in range(n):
  if A[i]%2==1:
    f=1
if f==0:
  print("YES")
else:
  print("NO")

Solution (Python):
N, M = map(int, input().split(' '))
count = [0 for _ in range(N)]

for _ in range(M):
    a, b = map(int, input().split(' '))
    count[a - 1] += 1
    count[b - 1] += 1

if all([c % 2 == 0 for c in count]):
    print('YES')
else:
    print('NO')

Solution (Python):
from collections import Counter

N, M = map(int, input().split())
X = [list(map(int, input().split())) for _ in range(M)]

ctr = Counter()
for a, b in X:
    ctr[a] += 1
    ctr[b] += 1

if all(v % 2 == 0 for v in ctr.values()):
    print("YES")
else:
    print("NO")

Solution (Python):
n, m = map(int,input().split())
num = [0 for i in range(n)]

for i in range(m):
    a,b = map(int,input().split())
    num[a-1] += 1
    num[b-1] += 1

for i in num:
    if i%2 == 1:
        print("NO")
        exit()

print("YES")

Solution (Python):
n,m = map(int, input().split())
d = [0]*n
for _ in range(m):
    a,b = map(int, input().split())
    d[a-1] += 1
    d[b-1] += 1

for x in d:
    if x%2==1:
        print("NO")
        exit()
print("YES")

Solution (Python):
n,m=map(int,input().split())
che=[0]*n
for i in range(m):
    a,b=map(int,input().split())
    che[a-1] += 1
    che[b-1] += 1
    
error=0
for i in range(n):
    if che[i]%2!=0:
        error += 1

if error==0:
    print('YES')
else:
    print('NO')

Solution (Python):
from collections import Counter
n,m = map(int,input().split())
ab_input = [int(j) for i in range(m) for j in input().split()]

ab_count = Counter(ab_input)
if all(v%2==0 for v in ab_count.values()):
    print('YES')
else:
    print('NO')

Solution (Python):
import sys
input = sys.stdin.readline
def main():
  n,m=map(int,input().split())
  ab=[list(map(int,input().split())) for _ in range(m)]
  c=[0]*n
  for a,b in ab:
    c[a-1]+=1
    c[b-1]+=1
  print('NO' if len([ci for ci in c if ci%2==1])>0 else 'YES')
if __name__=='__main__':
  main()

Solution (Python):
n,m=map(int,input().split())
l=[0]*(n+1)
for i in range(m):
    a,s=map(int,input().split())
    l[a]+=1
    l[s]+=1
for i in l:
    if i%2:print("NO");exit()
print("YES")

Solution (Python):
import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines
sys.setrecursionlimit(10 ** 7)

n, m = map(int, readline().split())
check = [0] * (n + 1)
for i in range(m):
    a, b = map(int, readline().split())
    check[a] += 1
    check[b] += 1
for v in check:
    if v % 2 == 1:
        print('NO')
        break
else:
    print('YES')

Solution (Python):
n,m = map(int,input().split())
ab = [0]*n
for _ in range(m):
    a, b = (int(x) for x in input().split())
    ab[a-1] += 1
    ab[b-1] += 1

flag = False

for i in ab:
    if i%2 == 1:
        flag = True
        break

if flag:
    print('NO')
else:
    print('YES')

Solution (Python):
N, M = map(int, input().split())
c = [0] * (N+1)

for _ in range(M):
    a, b = map(int, input().split())
    c[a] += 1
    c[b] += 1

print("YES" if all(c[i]%2 == 0 for i in range(N+1)) else "NO")

Solution (Python):
import sys

input = sys.stdin.readline


def main():
    N, M = map(int, input().split())

    cnt = [0] * (N + 1)
    for _ in range(M):
        a, b = map(int, input().split())
        cnt[a] += 1
        cnt[b] += 1

    ans = "YES" if all(c % 2 == 0 for c in cnt) else "NO"
    print(ans)


if __name__ == "__main__":
    main()

Solution (Python):
import sys

input = sys.stdin.readline


def main():
    N, M = map(int, input().split())

    cnt = [0] * N
    for _ in range(M):
        a, b = map(int, input().split())
        cnt[a - 1] += 1
        cnt[b - 1] += 1

    ans = "YES" if all(c % 2 == 0 for c in cnt) else "NO"
    print(ans)


if __name__ == "__main__":
    main()

Solution (Python):
import sys

input = sys.stdin.readline


def main():
    N, M = map(int, input().split())

    cnt = [0] * N
    for _ in range(M):
        a, b = map(int, input().split())
        cnt[a - 1] += 1
        cnt[b - 1] += 1

    ans = "YES"
    for c in cnt:
        if c % 2 != 0:
            ans = "NO"
    print(ans)


if __name__ == "__main__":
    main()

Solution (Python):
import sys

sys.setrecursionlimit(10 ** 7)
f_inf = float('inf')
mod = 10 ** 9 + 7


def resolve():
    n, m = map(int, input().split())

    cnt = [0] * n
    for i in range(m):
        a, b = map(int, input().split())
        cnt[a - 1] += 1
        cnt[b - 1] += 1

    for i in cnt:
        if i % 2:
            print("NO")
            break
    else:
        print("YES")


if __name__ == '__main__':
    resolve()

Solution (Python):

n,m = list(map(int, input().split()))
times = [0 for i in range(n)]
for i in range(m):
    t = list(map(int, input().split()))
    times[t[0]-1]+=1
    times[t[1]-1]+=1

ans = 1
for i in range(n):
    ans *= (times[i]+1)%2
    
if(ans==1):
    print("YES")
else:
    print("NO")

Solution (Python):
def main(sample_file = ''):

    """ convenient functions
    
    
    
    
    
    """

    """convenient decorator
    
    
        
        
        
        
        
        
        
        
        
        
    """
    
    
    import sys
    sys.setrecursionlimit(10**7)
    from itertools import accumulate, combinations, permutations, product 
    
    from math import factorial, ceil, floor, sqrt
    def factorize(n):
        """return the factors of the Arg and count of each factor
        
        Args:
            n (long): number to be resolved into factors
        
        Returns:
            list of tuples: factorize(220) returns [(2, 2), (5, 1), (11, 1)]
        """
        fct = []  
        b, e = 2, 0  
        while b * b <= n:
            while n % b == 0:
                n = n // b
                e = e + 1
            if e > 0:
                fct.append((b, e))
            b, e = b + 1, 0
        if n > 1:
            fct.append((n, 1))
        return fct
    def combinations_count(n, r):   
        """Return the number of selecting r pieces of items from n kinds of items.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        
        if n < 0 or r < 0:
            raise Exception('combinations_count(n, r) not defined when n or r is negative')
        if n - r < r: r = n - r
        if r < 0: return 0
        if r == 0: return 1
        if r == 1: return n
        numerator = [n - r + k + 1 for k in range(r)]
        denominator = [k + 1 for k in range(r)]
        for p in range(2,r+1):
            pivot = denominator[p - 1]
            if pivot > 1:
                offset = (n - r) % p
                for k in range(p-1,r,p):
                    numerator[k - offset] /= pivot
                    denominator[k] /= pivot
        result = 1
        for k in range(r):
            if numerator[k] > 1:
                result *= int(numerator[k])
        return result
    def combinations_with_replacement_count(n, r):
        """Return the number of selecting r pieces of items from n kinds of items allowing individual elements to be repeated more than once.
        
        Args:
            n (long): number
            r (long): number
        
        Raises:
            Exception: not defined when n or r is negative
        
        Returns:
            long: number
        """
        if n < 0 or r < 0:
            raise Exception('combinations_with_replacement_count(n, r) not defined when n or r is negative')
        elif n == 0:
            return 1
        else:
            return combinations_count(n + r - 1, r)
    from bisect import bisect_left, bisect_right
    from collections import deque, Counter, defaultdict 
    from heapq import heapify, heappop, heappush, heappushpop, heapreplace,nlargest,nsmallest 
    from copy import deepcopy, copy 
    import operator
    from operator import itemgetter 
    
    
    from functools import reduce, lru_cache
    def chmin(x, y):
        """change minimum
        if x > y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current minimum value
            y (long): potential minimum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x > y:
            x = y
            return (x, True)
        else:
            return (x, False)
    def chmax(x, y):
        """change maximum
        if x < y, x = y and return (x, True).
        convenient when solving problems of dp[i]
        
        Args:
            x (long): current maximum value
            y (long): potential maximum value
        
        Returns:
            (x, bool): (x, True) when updated, else (x, False)
        """
        if x < y:
            x = y
            return (x, True)
        else:
            return (x, False)

    from fractions import gcd 
    def gcds(numbers):
        return reduce(gcd, numbers)
    def lcm(x, y):
        return (x * y) // gcd(x, y)
    def lcms(numbers):
        return reduce(lcm, numbers, 1)
    def make_divisors(n, reversed=False):
        """create list of divisors
        
        Args:
            number (int): number from which list of divisors is created
            reversed (bool, optional): ascending order if False. Defaults to False.
        
        Returns:
            list: list of divisors
        """
        divisors = set()
        for i in range(1, int(n**0.5)+1):
            if n % i == 0:
                divisors.add(i)
                divisors.add(n//i)
        return sorted(list(divisors),reverse=reversed)
    
    
    
    INF = 10 ** 18
    MOD = 10 ** 9 + 7
    AtoZ = list('abcdefghijklmnopqrsruvwxyz')
    modpow = lambda a, n, p = MOD: pow(a, n, p) 
    def modinv(a, p = MOD):
        
        
        return modpow(a, p-2, p)
    def modinv_list(n, p = MOD):
        if n <= 1:
            return [0,1][:n+1]
        else:
            inv_t = [0,1]
            for i in range(2, n+1):
                inv_t += [inv_t[p % i] * (p - int(p / i)) % p]
            return inv_t
    def modfactorial_list(n, p = MOD):
        if n == 0:
            return [1]
        else:
            l = [0] * (n+1)
            tmp = 1
            for i in range(1, n+1):
                tmp = tmp * i % p
                l[i] = tmp
            return l
    def modcomb(n, k, fac_list = [], p = MOD):
        
        
        from math import factorial
        if n < 0 or k < 0 or n < k: return 0
        if n == 0 or k == 0: return 1
        if len(fac_list) <= n:
            a = factorial(n) % p
            b = factorial(k) % p
            c = factorial(n-k) % p
        else:
            a = fac_list[n]
            b = fac_list[k]
            c = fac_list[n-k]
        return (a * modpow(b, p-2, p) * modpow(c, p-2, p)) % p
    def modadd(a, b, p = MOD):
        return (a + b) % MOD
    def modsub(a, b, p = MOD):
        return (a - b) % p
    def modmul(a, b, p = MOD):
        return ((a % p) * (b % p)) % p
    def moddiv(a, b, p = MOD):
        return modmul(a, modpow(b, p-2, p))

    class UnionFindTree:
        """union find tree class
        TODO: fix this description...
        how to use (example):
        >>  uf = UnionFindTree(N) 
        >>  if uf.find_root(a) == uf.find_root(b):
        >>      do something
        >>  else:
        >>      do something
        >>      uf.unite(a, b)
        """
        def __init__(self, N):
            self.root = [-1] * (N+1)
            self.rank   = [0]  * (N+1)
            self.connected_num = [1] * (N+1)
    
        def find_root(self,x):
            root = self.root
            while root[x] != -1:
                x = root[x]
            return x
    
        def unite(self,x,y):
            root = self.root
            rank = self.rank
            connected_num = self.connected_num
            find_root = self.find_root
    
            rx = find_root(x)
            ry = find_root(y)
            if rx != ry:
                if rank[rx] < rank[ry]:
                    root[rx] = ry
                    rx,ry = ry,rx
                else:
                    if rank[rx] == rank[ry]:
                        rank[rx] += 1
                    root[ry] = rx       
                connected_num[rx] += connected_num[ry]

    
    
    
    
    
    
    
    

    def BellmanFord(N, M, ABC, vertex_start, vertex_end, value_if_inf = -1, find_shortest = False):
        """to calculate furthest or shortest length between vertex_start and vertex_end using BellmanFord algorithm
        
        Args:
            N (int): number of vertices
            M (int): number of edges
            ABC (list): [(ai, bi, ci) for _ in range(N)] where i-th edge is directed from vertex ai to vertex bi and the length is ci 
            vertex_start (int): start vertex. usually use 0.
            vertex_end (int): end vertex. usually use N-1.
            value_if_inf (int or string as you like, optional): value you want when the furthest (or shortest) distance is infinite (or -infinite). Defaults to -1.
            find_shortest (bool, optional): choose False to find furthest path. Defaults to False.
        
        Returns:
            int or string: normally int (but can be str if you set value_if_inf to str)
            
        Example:
                N, M, P = R()
                ABC = [R() for _ in range(M)]
                ABC = [(a-1, b-1, c-P) for a, b, c in ABC]
                print(BellmanFord(N, M, ABC, 0, N-1, value_if_inf = 'inf'))

        """

        def make_reachable_list(N, M, ABC, vertex_start, vertex_end):
            reachable_to_direct = defaultdict(list)
            reachable_from_direct = defaultdict(list)
            reachable_from_start = [False] * N
            reachable_to_end = [False] * N
            reachable_from_start[vertex_start] = True
            reachable_to_end[vertex_end] = True
            reachable_from_both_sides = [False] * N
            dfs_from_start = []
            dfs_to_end = []
            for a, b, c in ABC:
                reachable_to_direct[a].append(b)
                reachable_from_direct[b].append(a)
                if a == vertex_start:
                    dfs_from_start.append(b)
                    reachable_from_start[b] = True
                if b == vertex_end:
                    dfs_to_end.append(a)
                    reachable_to_end[a] = True
            while dfs_from_start:
                v = dfs_from_start.pop()
                for i in reachable_to_direct[v]:
                    if not reachable_from_start[i]:
                        reachable_from_start[i] = True
                        dfs_from_start.append(i)
            while dfs_to_end:
                v = dfs_to_end.pop()
                for i in reachable_from_direct[v]:
                    if not reachable_to_end[i]:
                        reachable_to_end[i] = True
                        dfs_to_end.append(i)
            for i in range(N):
                reachable_from_both_sides[i] = reachable_from_start[i] and reachable_to_end[i]
            return reachable_from_both_sides
        
        reachable_from_both_sides = make_reachable_list(N, M, ABC, vertex_start, vertex_end)
        
        if find_shortest:
            dist = [INF for i in range(N)]
        else:
            dist = [-INF for i in range(N)]
        
        dist[vertex_start] = 0
        for i in range(N):
            updated = False
            for a, b, c in ABC:
                if not reachable_from_both_sides[a]:
                    continue
                elif find_shortest:
                    update_condition = dist[a] + c < dist[b]
                else:
                    update_condition = dist[a] + c > dist[b]
                if dist[a] != INF and update_condition:
                    dist[b] = dist[a] + c
                    updated = True
                    if i == N-1:
                        return value_if_inf
            if not updated:
                break
        return dist[vertex_end]

    
    def warshall_floyd(number_vertex, XYD, shift_one_for_vertex=False):
        
        
        
        
        
        d = [[float("inf")]*number_vertex for i in range(number_vertex)]
        for x, y, dist in XYD:
            if shift_one_for_vertex:
                x = x - 1
                y = y - 1
            d[x][y] = dist
            d[y][x] = dist
        for i in range(number_vertex):
            d[i][i] = 0 
        for k in range(number_vertex):
            for i in range(number_vertex):
                for j in range(number_vertex):
                    d[i][j] = min(d[i][j],d[i][k] + d[k][j])
        return d


    """ initialize variables and set inputs
    
        
        
            
            
    
        
        
        
        
        
        
        
    
        
        
        
        
    
        
        
    """

    
    r = lambda: sys.stdin.readline().strip()
    r_int = lambda: int(r())
    r_float = lambda: float(r())
    R = lambda: list(map(int, r().split()))
    R_str = lambda: r().split()
    R_map = lambda: map(int, r().split())
    R_float = lambda: list(map(float, r().split()))
    R_tuple = lambda: tuple(map(int, r().split()))

    """ how to treat input
    
    
    
    
    
    
    
    """

    
    if sample_file:
        sys.stdin = open(sample_file)
        
    
    
    
    N, M = R()
    AB = [R() for i in range(M)]
    l = [0] * N
    for a, b in AB:
        l[a-1] += 1
        l[b-1] += 1
    flag = True
    for ll in l:
        if ll%2 != 0:
            flag = False
    if flag:
        print('YES')
    else:
        print('NO')

    
    
    

    """memo: how to use defaultdict of list
    
    Dic = defaultdict(list)
    
    Dic[x].append(y)
    
    for k, v in Dic.items():
    """
    
    """memo: how to solve binary problems
    
    >>> a = 5
    >>> bin_str_a = format(a, '
    >>> print(bin_str_a)
    0b0101 
    """
    
    """memo: how to solve the problem
    creating simple test/answer
    greed
    simple dp
    graph
    """

if __name__ == '__main__':
    main()

Solution (Python):
n, m = map(int, input().split())

tree = [0 for _ in range(n+1)]
for _i in range(m):
    a, b = map(int, input().split())
    tree[a] += 1
    tree[b] += 1
if all(i%2==0 for i in tree):
    print("YES")
else:
    print("NO")

Solution (Python):
n, m = map(int, input().split())

tree = [0 for _ in range(n+1)]
for _i in range(m):
    a, b = map(int, input().split())
    tree[a] += 1
    tree[b] += 1
if all(i%2==0 for i in tree):
    print("YES")
else:
    print("NO")

Solution (Python):

"""
今回は各辺の偶奇のみを考えるので、
根付き木を考えた時に、頂点a,bから親側に全部流した時に、
LCAより先は勝手に偶数になるので無視できる。
とした場合に、根をrootとして、各クエリに対して
a-root,b-rootへのパスに1を足すことと考えると、
結局各辺の偶奇はaとbの出現回数の偶奇によると考える事ができる。
よって、クエリに与えられる辺の回数をdictで保持し、
最終的に一つでも奇数回出現する頂点があるならばFalse
そうでないならTrueとなる

"""
import sys
from collections import defaultdict
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
n,m = map(int,readline().split())
dic1 = defaultdict(int)
for i in range(m):
    a,b = map(int,readline().split())
    dic1[a] += 1
    dic1[b] += 1

for i in dic1.values():
    if not even(i):
        print("NO")
        exit()
print("YES")

Solution (Python):

import sys
from collections import defaultdict
readline = sys.stdin.buffer.readline
def even(n): return 1 if n%2==0 else 0
n,m = map(int,readline().split())
dic1 = defaultdict(int)
for i in range(m):
    a,b = map(int,readline().split())
    dic1[a] += 1
    dic1[b] += 1

for i in dic1.values():
    if not even(i):
        print("NO")
        exit()
print("YES")

Solution (Python):
N,M=map(int,input().split())

count=[0]*N
for _ in range(M):
    a,b=map(int,input().split())
    count[a-1]+=1
    count[b-1]+=1

for c in count:
    if c%2==1:
        print("NO")
        exit()

print("YES")

Solution (Python):
n,m = map(int,input().split())
ab = [[int(i) for i in input().split()] for j in range(m)]

im_b = [0]*(n)

for i in range(m):
    im_b[ab[i][0]-1] += 1
    im_b[ab[i][1]-1] -= 1

if im_b[0] % 2 == 1:
    print('NO')
    exit()




for i in range(n-1):
    
    if im_b[i] % 2 == 1:
        print('NO')
        exit()

print('YES')

Solution (Python):
c = [0]*10**5
for i in open(0).read().split()[2:]: c[int(i)-1] ^= 1
print("NO" if any(c) else "YES")

Solution (Python):
n,m = map(int, input().split())
ab=[list(map(int,input().split())) for i in range(m)]
cnt=[0]*n

for tmp in ab:
    a,b=tmp
    cnt[a-1]+=1
    cnt[b-1]+=1

for c in cnt:
    if c%2!=0:
        print("NO")
        exit()
print("YES")

Solution (Python):
n,m = map(int,input().split())
from collections import Counter

s = []
for _ in range(m):
    a,b = map(int,input().split())
    s.append(a)
    s.append(b)
    
c = Counter(s)
d = list(c.values())

ans = "YES"
for i in d:
    if i % 2 == 1:
        ans = "NO"
        break
        
print(ans)

Solution (Python):
import sys
import math  
import bisect  
import queue  


def input():
    return sys.stdin.readline().rstrip()


def main():
    N, M = map(int, input().split())
    cnt = [0 for _ in range(N)]
    for _ in range(M):
        a, b = map(int, input().split())
        a -= 1
        b -= 1
        cnt[a] += 1
        cnt[b] += 1

    for c in cnt:
        if c % 2 != 0:
            return print("NO")

    print("YES")


if __name__ == '__main__':
    main()

Solution (Python):
N,M=map(int, input().split())

D={} 
for i in range(N):
  D[i+1]=0
for i in range(M):
  a,b=map(int, input().split())
  D[a]+=1
  D[b]+=1

odds=0
evens=0
for v in D.values():
    if v%2==0:
        evens+=1
    else:
        odds+=1
if odds>0:
    print("NO")
else:
    print("YES")

Solution (Python):
N, M = map(int, input().split())
C = [0] * N
for i in range(M):
    ai, bi = map(int, input().split())
    C[ai - 1] += 1
    C[bi - 1] += 1

print('YES' if len(list(filter(lambda i: i % 2 == 1, C))) == 0 else 'NO')

Solution (Python):
c=[0]*9**6
for x in open(0).read().split()[2:]:c[int(x)]^=1
print("YNEOS"[any(c)::2])

Solution (Python):
c=[0]*9**6
for x in open(0).read().split()[2:]:c[int(x)]^=1
print("YNEOS"[any(c)::2])

Solution (Python):
n,m,*p=map(int,open(0).read().split());c=[0]*n
for x in p:c[x-1]+=1
print("YNEOS"[any(x%2for x in c)::2])

Solution (Python):
from collections import Counter

N, M = map(int, input().split())
counter = Counter()
for i in range(M):
    a, b = map(int, input().split())
    counter[a] += 1
    counter[b] += 1

if all(x % 2 == 0 for x in counter.values()):
    print("YES")
else:
    print("NO")

Solution (Python):
N,M=map(int,input().split())
G=[]
x=dict()
for i in range(M):
    a,b=map(int,input().split())
    if a in x:
        x[a]+=1
    else:
        x[a]=1
    if b in x:
        x[b]+=1
    else:
        x[b]=1

flag=True
for idx in x:
    if x[idx]%2==0:
        pass
    else:
        flag=False

if flag:
    print("YES")
else:
    print("NO")

Solution (Python):
import sys,collections as cl,bisect as bs
sys.setrecursionlimit(100000)
input = sys.stdin.readline
mod = 10**9+7
Max = sys.maxsize
def l(): 
    return list(map(int,input().split()))
def m(): 
    return map(int,input().split())
def onem(): 
    return int(input())
def s(x): 
    a = []
    if len(x) == 0:
        return []
    aa = x[0]
    su = 1
    for i in range(len(x)-1):
        if aa != x[i+1]:
            a.append([aa,su])
            aa = x[i+1]
            su = 1
        else:
            su += 1
    a.append([aa,su])
    return a
def jo(x): 
    return " ".join(map(str,x))
def max2(x): 
    return max(map(max,x))
def In(x,a): 
    k = bs.bisect_left(a,x)
    if k != len(a) and a[k] ==  x:
        return True
    else:
        return False

def pow_k(x, n):
    ans = 1
    while n:
        if n % 2:
            ans *= x
        x *= x
        n >>= 1
    return ans

"""
def nibu(x,n,r):
    ll = 0
    rr = r
    while True:
        mid = (ll+rr)//2

    if rr == mid:
        return ll
    if (ここに評価入れる):
        rr = mid
    else:
        ll = mid+1
"""

n,k = m()

po = [0 for i in range(n)]

for i in range(k):
    a,b = m()
    po[a-1] += 1
    po[b-1] += 1
if all(map(lambda x:x%2 == 0,po)):
    print("YES")
else:
    print("NO")

Solution (Python):
N, M = map(int, input().split())
ab = []
for _ in range(M):
    ab.append(tuple(map(int, input().split())))

bucket = [0] * N
for el in ab:
    a, b = el
    bucket[a - 1] += 1
    bucket[b - 1] += 1
if all([x % 2 == 0 for x in bucket]):
    print('YES')
else:
    print('NO')

Solution (Python):
N, M = map(int, input().split())
ab = []
for _ in range(M):
    ab.append(tuple(map(int, input().split())))

edges = [0] * N
for el in ab:
    a = min(el)
    b = max(el)
    edges[a - 1] += 1
    edges[b - 1] -= 1

for i in range(1, N):
    edges[i] = edges[i] + edges[i - 1]


if all([x % 2 == 0 for x in edges]):
    print('YES')
else:
    print('NO')

Solution (Python):
n, m = map(int, input().split())
count = [0 for i in range(n+1)]
for i in range(m):
    a,b = map(int, input().split())
    count[a] += 1
    count[b] += 1
for i in range(n+1):
    if count[i] % 2 != 0:
        print("NO")
        exit()
print("YES")

Solution (Python):
from collections import defaultdict as d
N,M=map(int,input().split())
E=d(int)
for i in range(M):
  a,b=map(int,input().split())
  E[a]^=1
  E[b]^=1
print(("YES","NO")[max(E.values())])

Solution (Python):

from collections import defaultdict as d

N,M = map(int,input().split())
E = d(int)

for i in range(M):
  a,b = map(int,input().split())
  E[a] ^= 1
  E[b] ^= 1

print(("YES","NO")[sorted(E.values())[-1]])

Solution (Python):
import sys
N, M = [int(i) for i in sys.stdin.readline().split()]
v = [0] * N
for _ in range(M):
    a, b = map(int, sys.stdin.readline().split())
    v[a - 1] ^= 1
    v[b - 1] ^= 1
print("NO" if 1 in v else "YES")

Solution (Python):
n,m=map(int,input().split())
a=[0]*(n+1)
for i in range(m):
  x,y=map(int,input().split())
  a[x]+=1
  a[y]+=1
ans='YES'
for i in range(1,n+1):
  if a[i]%2==1:
    ans='NO'
    break
print(ans)

Solution (Python):







import sys
sys.setrecursionlimit(1 << 25)
read = sys.stdin.readline
ra = range
enu = enumerate


def read_ints():
    return list(map(int, read().split()))


N, M = read_ints()

n_edges = [0] * N
for _ in ra(M):
    a, b = read_ints()
    n_edges[a - 1] += 1
    n_edges[b - 1] += 1

for n in n_edges:
    if n & 1:
        print('NO')
        exit()
print('YES')

Solution (Python):
N, M = map(int, input().split())
cnt = [0] * (N+1)
for _ in range(M):
    ta,tb = map(int, input().split())
    cnt[ta] += 1
    cnt[tb] += 1
cond = 0
for i in range(1,N+1):
    if cnt[i] % 2 == 1:
        cond = 1
        break

if cond:
    print('NO')
else:
    print('YES')

Solution (Python):

from collections import defaultdict,deque
from heapq import heappush, heappop
from bisect import bisect_left, bisect_right
import sys, random, itertools, math
sys.setrecursionlimit(10**5)
input = sys.stdin.readline
sqrt = math.sqrt
def LI(): return list(map(int, input().split()))
def LF(): return list(map(float, input().split()))
def LI_(): return list(map(lambda x: int(x)-1, input().split()))
def II(): return int(input())
def IF(): return float(input())
def S(): return input().rstrip()
def LS(): return S().split()
def IR(n): return [II() for _ in range(n)]
def LIR(n): return [LI() for _ in range(n)]
def FR(n): return [IF() for _ in range(n)]
def LFR(n): return [LI() for _ in range(n)]
def LIR_(n): return [LI_() for _ in range(n)]
def SR(n): return [S() for _ in range(n)]
def LSR(n): return [LS() for _ in range(n)]
mod = 1000000007
inf = 1e10


def solve():
    n, m = LI()
    l = [0] * n
    for i in range(m):
        a, b = LI_()
        l[a] ^= 1
        l[b] ^= 1
    print("NO" if sum(l) else "YES")
    return



if __name__ == '__main__':
    solve()

Solution (Python):
N,M = list(map(int, input().split()))
n = [0]*(N+1)
for _ in range(M):
    a,b = list(map(int, input().split()))
    n[a] += 1
    n[b] += 1


flag = True
for j in range(len(n)):
    if n[j]%2 != 0:
        flag = False

if flag:
    print('YES')
else:
    print('NO')

Solution (Python):
import sys
input = sys.stdin.readline
from collections import *

N, M = map(int, input().split())
dic = defaultdict(int)
for i in range(M):
    a, b = map(int, input().split())
    dic[a] += 1
    dic[b] += 1
if any([x&1 for x in dic.values()]):
    print('NO')
else:
    print('YES')