def find(x):
    if P[x] == x:
        return x
    else:
        P[x] = find(P[x])  # 経路圧縮
        return P[x]

def same(x, y):
    return find(x) == find(y)

def unite(x, y):
    x = find(x)
    y = find(y)
    if x == y: return 0
    if x > y: x, y = y, x
    P[y] = x

N, M = map(int, input().split())
AB = [list(map(int, input().split())) for _ in range(M)]
P = [i for i in range(2 * (N + 1))]

for a, b in AB:
    unite(a, b + N)
    unite(a + N, b)

for i in range(1, N + 1):
    if not same(i, i + N):
        print("No")
        break
else:
    print("Yes")