题解 | #幼儿园分班#

def cls():
    m = int(input())
    n = int(input())
    ls = []
    cls1 = []
    cls2 = []
    for i in range(n):
        a,b = map(int,input().strip().split())
        if a in cls1:
            cls2.append(b)
        elif a in cls2:
            cls1.append(b)
        else:
            cls1.append(a)
            cls2.append(b)
        ls.append(a)
        ls.append(b)
    res = sorted(list(set(cls1)) + list(set(cls2)))
    ls_res = sorted(list(set(ls)))
    if res == ls_res:
        print(1)
    else:
        print(0)
cls()