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

edge = [[] for _ in range(N)]

edges = [(0,0) for _ in range(M)]

for i in range(M):

    a,b = list(map(int, input().split()))

    edge[a-1].append(b-1)

    edge[b-1].append(a-1)

    edges[i] = (a-1,b-1)



import sys

sys.setrecursionlimit(10**8)



def dfs(v, es):

    #print(h,w)

    if len(es[v])==0:

        return 0

    for u in es[v]:

        if visited[u]==False:

            visited[u]=True

            dfs(u,es)

    return 0



import copy

ans = 0

for i in range(M):

    visited = [False]*N

    a,b = edges[i]

    es = copy.deepcopy(edge)

    # print(edge,a,b)

    es[a].remove(b)

    es[b].remove(a)

    for v in range(N):

        if visited[v]==False:

            visited[v]=True

            dfs(v,es)

            if False in visited:

                # print(a,b)

                break

    else:

        continue

    ans += 1

print(ans)
class UnionFind():

    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 same(self, x, y):

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



    def nums(self,x):

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



    def roots(self):

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



    def members(self, x):

        root = self.find(x)

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



    def __str__(self):

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



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

A = [0]*M

B = [0]*M

for i in range(M):

    A[i],B[i] = list(map(int, input().split()))

ans = 0

for i in range(M):

    uf = UnionFind(N)

    for j in range(M):

        if j!=i:

            uf.union(A[j]-1,B[j]-1)

    if len(uf.roots())>1:

        ans += 1

print(ans)
N, M = list(map(int, input().split()))
edge = [[] for _ in range(N)]
edges = [(0, 0) for _ in range(M)]
for i in range(M):
    a, b = list(map(int, input().split()))
    edge[a - 1].append(b - 1)
    edge[b - 1].append(a - 1)
    edges[i] = (a - 1, b - 1)
import sys

sys.setrecursionlimit(10**8)


def dfs(v, es):
    # print(h,w)
    if len(es[v]) == 0:
        return 0
    for u in es[v]:
        if visited[u] == False:
            visited[u] = True
            dfs(u, es)
    return 0


import copy

ans = 0
for i in range(M):
    visited = [False] * N
    a, b = edges[i]
    es = copy.deepcopy(edge)
    # print(edge,a,b)
    es[a].remove(b)
    es[b].remove(a)
    for v in range(N):
        if visited[v] == False:
            visited[v] = True
            dfs(v, es)
            if False in visited:
                # print(a,b)
                break
    else:
        continue
    ans += 1
print(ans)

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

    def nums(self, x):
        return abs(self.parents[self.find(x)])

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

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

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


N, M = list(map(int, input().split()))
A = [0] * M
B = [0] * M
for i in range(M):
    A[i], B[i] = list(map(int, input().split()))
ans = 0
for i in range(M):
    uf = UnionFind(N)
    for j in range(M):
        if j != i:
            uf.union(A[j] - 1, B[j] - 1)
    if len(uf.roots()) > 1:
        ans += 1
print(ans)

-N, M = list(map(int, input().split())) -edge = [[] for _ in range(N)] -edges = [(0, 0) for _ in range(M)] -for i in range(M): -    a, b = list(map(int, input().split())) -    edge[a - 1].append(b - 1) -    edge[b - 1].append(a - 1) -    edges[i] = (a - 1, b - 1) -import sys +class UnionFind: +    def __init__(self, n): +        self.n = n +        self.parents = [-1] * n -sys.setrecursionlimit(10**8) +    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 same(self, x, y): +        return self.find(x) == self.find(y) + +    def nums(self, x): +        return abs(self.parents[self.find(x)]) + +    def roots(self): +        return [i for i, x in enumerate(self.parents) if x < 0] + +    def members(self, x): +        root = self.find(x) +        return [i for i in range(self.n) if self.find(i) == root] + +    def __str__(self): +        return "\n".join("{}: {}".format(r, self.members(r)) for r in self.roots()) -def dfs(v, es): -    # print(h,w) -    if len(es[v]) == 0: -        return 0 -    for u in es[v]: -        if visited[u] == False: -            visited[u] = True -            dfs(u, es) -    return 0 - - -import copy - +N, M = list(map(int, input().split())) +A = [0] * M +B = [0] * M +for i in range(M): +    A[i], B[i] = list(map(int, input().split())) -    visited = [False] * N -    a, b = edges[i] -    es = copy.deepcopy(edge) -    # print(edge,a,b) -    es[a].remove(b) -    es[b].remove(a) -    for v in range(N): -        if visited[v] == False: -            visited[v] = True -            dfs(v, es) -            if False in visited: -                # print(a,b) -                break -    else: -        continue -    ans += 1 +    uf = UnionFind(N) +    for j in range(M): +        if j != i: +            uf.union(A[j] - 1, B[j] - 1) +    if len(uf.roots()) > 1: +        ans += 1