import sys



read = sys.stdin.read

readline = sys.stdin.readline

readlines = sys.stdin.readlines

sys.setrecursionlimit(10 ** 9)

INF = 1 << 60





class UnionFind:

    # Reference: https://note.nkmk.me/python-union-find/

    def __init__(self, n):

        self.n = n

        self.parents = [-1] * n



    def find(self, x):

        if self.parents[x] < 0:

            return x

        else:

            self.parents[x] = self.find(self.parents[x])

            return self.parents[x]



    def union(self, x, y):

        x = self.find(x)

        y = self.find(y)



        if x == y:

            return



        if self.parents[x] > self.parents[y]:

            x, y = y, x



        self.parents[x] += self.parents[y]

        self.parents[y] = x



    def size(self, x):

        return -self.parents[self.find(x)]



    def same(self, x, y):

        return self.find(x) == self.find(y)



    def members(self, x):

        root = self.find(x)

        return [i for i in range(self.n) if self.find(i) == root]



    def roots(self):

        return [i for i, x in enumerate(self.parents) if x < 0]



    def group_count(self):

        return len(self.roots())



    def all_group_members(self):

        return {r: self.members(r) for r in self.roots()}



    def __str__(self):

        return '\n'.join('{}: {}'.format(r, self.members(r)) for r in self.roots())





N, M, *AB = list(map(int, read().split()))

A = AB[::2]

B = AB[1::2]



ans = 0

for i in range(M):

    uf = UnionFind(N)

    for j, (a, b) in enumerate(zip(A, B)):

        if i != j:

            uf.union(a - 1, b - 1)

    if uf.group_count() > 1:

        ans += 1



print(ans)

import sys



read = sys.stdin.read

readline = sys.stdin.readline

readlines = sys.stdin.readlines

sys.setrecursionlimit(10 ** 9)

INF = 1 << 60





class UnionFind:

    # Reference: https://note.nkmk.me/python-union-find/

    def __init__(self, n):

        self.n = n

        self.parents = [-1] * n



    def find(self, x):

        if self.parents[x] < 0:

            return x

        else:

            self.parents[x] = self.find(self.parents[x])

            return self.parents[x]



    def union(self, x, y):

        x = self.find(x)

        y = self.find(y)



        if x == y:

            return



        if self.parents[x] > self.parents[y]:

            x, y = y, x



        self.parents[x] += self.parents[y]

        self.parents[y] = x



    def size(self, x):

        return -self.parents[self.find(x)]



    def same(self, x, y):

        return self.find(x) == self.find(y)



    def members(self, x):

        root = self.find(x)

        return [i for i in range(self.n) if self.find(i) == root]



    def roots(self):

        return [i for i, x in enumerate(self.parents) if x < 0]



    def group_count(self):

        return len(self.roots())





def main():

    N, M = list(map(int, readline().split()))

    AB = [[int(s) - 1 for s in line.split()] for line in readlines()]



    ans = 0

    for i in range(M):

        uf = UnionFind(N)

        for j, (a, b) in enumerate(AB):

            if i == j:

                continue

            uf.union(a, b)

        if uf.group_count() > 1:

            ans += 1



    print(ans)

    return





if __name__ == '__main__':

    main()

import sys

read = sys.stdin.read
readline = sys.stdin.readline
readlines = sys.stdin.readlines
sys.setrecursionlimit(10**9)
INF = 1 << 60


class UnionFind:
    # Reference: https://note.nkmk.me/python-union-find/
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return
        if self.parents[x] > self.parents[y]:
            x, y = y, x
        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

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

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())

    def all_group_members(self):
        return {r: self.members(r) for r in self.roots()}

    def __str__(self):
        return "\n".join("{}: {}".format(r, self.members(r)) for r in self.roots())


N, M, *AB = list(map(int, read().split()))
A = AB[::2]
B = AB[1::2]
ans = 0
for i in range(M):
    uf = UnionFind(N)
    for j, (a, b) in enumerate(zip(A, B)):
        if i != j:
            uf.union(a - 1, b - 1)
    if uf.group_count() > 1:
        ans += 1
print(ans)

import sys

read = sys.stdin.read
readline = sys.stdin.readline
readlines = sys.stdin.readlines
sys.setrecursionlimit(10**9)
INF = 1 << 60


class UnionFind:
    # Reference: https://note.nkmk.me/python-union-find/
    def __init__(self, n):
        self.n = n
        self.parents = [-1] * n

    def find(self, x):
        if self.parents[x] < 0:
            return x
        else:
            self.parents[x] = self.find(self.parents[x])
            return self.parents[x]

    def union(self, x, y):
        x = self.find(x)
        y = self.find(y)
        if x == y:
            return
        if self.parents[x] > self.parents[y]:
            x, y = y, x
        self.parents[x] += self.parents[y]
        self.parents[y] = x

    def size(self, x):
        return -self.parents[self.find(x)]

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

    def members(self, x):
        root = self.find(x)
        return [i for i in range(self.n) if self.find(i) == root]

    def roots(self):
        return [i for i, x in enumerate(self.parents) if x < 0]

    def group_count(self):
        return len(self.roots())


def main():
    N, M = list(map(int, readline().split()))
    AB = [[int(s) - 1 for s in line.split()] for line in readlines()]
    ans = 0
    for i in range(M):
        uf = UnionFind(N)
        for j, (a, b) in enumerate(AB):
            if i == j:
                continue
            uf.union(a, b)
        if uf.group_count() > 1:
            ans += 1
    print(ans)
    return


if __name__ == "__main__":
    main()

-    def all_group_members(self): -        return {r: self.members(r) for r in self.roots()} -    def __str__(self): -        return "\n".join("{}: {}".format(r, self.members(r)) for r in self.roots()) +def main(): +    N, M = list(map(int, readline().split())) +    AB = [[int(s) - 1 for s in line.split()] for line in readlines()] +    ans = 0 +    for i in range(M): +        uf = UnionFind(N) +        for j, (a, b) in enumerate(AB): +            if i == j: +                continue +            uf.union(a, b) +        if uf.group_count() > 1: +            ans += 1 +    print(ans) +    return -N, M, *AB = list(map(int, read().split())) -A = AB[::2] -B = AB[1::2] -ans = 0 -for i in range(M): -    uf = UnionFind(N) -    for j, (a, b) in enumerate(zip(A, B)): -        if i != j: -            uf.union(a - 1, b - 1) -    if uf.group_count() > 1: -        ans += 1 -print(ans) +if __name__ == "__main__": +    main()