import sys, re, os

from collections import deque, defaultdict, Counter

from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians

from itertools import permutations, combinations, product, accumulate

from operator import itemgetter, mul

from copy import deepcopy

from string import ascii_lowercase, ascii_uppercase, digits

from fractions import gcd

from heapq import heapify, heappop, heappush



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

def INT(): return int(eval(input()))

def MAP(): return list(map(int, input().split()))

def S_MAP(): return list(map(str, input().split()))

def LIST(): return list(map(int, input().split()))

def S_LIST(): return list(map(str, input().split()))

 

sys.setrecursionlimit(10 ** 9)

INF = float('inf')

mod = 10 ** 9 + 7



N, M = MAP()

L = [LIST() for i in range(M)]



def dijkstra(E, start):

    N_d = len(E)

    dist = [INF] * N_d

    dist[start] = 0

    q = [(0, start)]

    while q:

        dist_v, v = heappop(q)

        if dist[v] != dist_v:

            continue

        for u, dist_vu in E[v]:

            dist_u = dist_v + dist_vu

            if dist_u < dist[u]:

                dist[u] = dist_u

                heappush(q, (dist_u, u))

    return dist



graph = defaultdict(list)

for a, b in L:

    graph[a-1].append((b-1, 1))

    graph[b-1].append((a-1, 1))



ans = 0

for a, b in L:

    E = deepcopy(graph)

    E[a-1].remove((b-1, 1))

    E[b-1].remove((a-1, 1))

    d = dijkstra(E, a-1)

    if d[b-1] == INF:

        ans += 1

print(ans)
import sys, re, os

from collections import deque, defaultdict, Counter

from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians

from itertools import permutations, combinations, product, accumulate

from operator import itemgetter, mul

from copy import deepcopy

from string import ascii_lowercase, ascii_uppercase, digits

from heapq import heapify, heappop, heappush



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

def INT(): return int(eval(input()))

def MAP(): return list(map(int, input().split()))

def S_MAP(): return list(map(str, input().split()))

def LIST(): return list(map(int, input().split()))

def S_LIST(): return list(map(str, input().split()))

 

sys.setrecursionlimit(10 ** 9)

INF = float('inf')

mod = 10 ** 9 + 7



def dijkstra(E, start):

    N_d = len(E)

    dist = [INF] * N_d

    dist[start] = 0

    q = [(0, start)]

    while q:

        dist_v, v = heappop(q)

        if dist[v] != dist_v:

            continue

        for u, dist_vu in E[v]:

            dist_u = dist_v + dist_vu

            if dist_u < dist[u]:

                dist[u] = dist_u

                heappush(q, (dist_u, u))

    return dist





N, M = MAP()

L = [LIST() for i in range(M)]

graph = defaultdict(list)



for a, b in L:

    graph[a-1].append((b-1, 1))

    graph[b-1].append((a-1, 1))



ans = 0



for i in range(M):

    a, b = L[i]

    E = deepcopy(graph)

    E[a-1].remove((b-1, 1))

    E[b-1].remove((a-1, 1))

    dist = dijkstra(E, 0)

    if dist.count(INF) > 0:

        ans += 1



print(ans)



import sys, re, os
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians
from itertools import permutations, combinations, product, accumulate
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from fractions import gcd
from heapq import heapify, heappop, heappush


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


def INT():
    return int(eval(input()))


def MAP():
    return list(map(int, input().split()))


def S_MAP():
    return list(map(str, input().split()))


def LIST():
    return list(map(int, input().split()))


def S_LIST():
    return list(map(str, input().split()))


sys.setrecursionlimit(10**9)
INF = float("inf")
mod = 10**9 + 7
N, M = MAP()
L = [LIST() for i in range(M)]


def dijkstra(E, start):
    N_d = len(E)
    dist = [INF] * N_d
    dist[start] = 0
    q = [(0, start)]
    while q:
        dist_v, v = heappop(q)
        if dist[v] != dist_v:
            continue
        for u, dist_vu in E[v]:
            dist_u = dist_v + dist_vu
            if dist_u < dist[u]:
                dist[u] = dist_u
                heappush(q, (dist_u, u))
    return dist


graph = defaultdict(list)
for a, b in L:
    graph[a - 1].append((b - 1, 1))
    graph[b - 1].append((a - 1, 1))
ans = 0
for a, b in L:
    E = deepcopy(graph)
    E[a - 1].remove((b - 1, 1))
    E[b - 1].remove((a - 1, 1))
    d = dijkstra(E, a - 1)
    if d[b - 1] == INF:
        ans += 1
print(ans)

import sys, re, os
from collections import deque, defaultdict, Counter
from math import ceil, sqrt, hypot, factorial, pi, sin, cos, radians
from itertools import permutations, combinations, product, accumulate
from operator import itemgetter, mul
from copy import deepcopy
from string import ascii_lowercase, ascii_uppercase, digits
from heapq import heapify, heappop, heappush


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


def INT():
    return int(eval(input()))


def MAP():
    return list(map(int, input().split()))


def S_MAP():
    return list(map(str, input().split()))


def LIST():
    return list(map(int, input().split()))


def S_LIST():
    return list(map(str, input().split()))


sys.setrecursionlimit(10**9)
INF = float("inf")
mod = 10**9 + 7


def dijkstra(E, start):
    N_d = len(E)
    dist = [INF] * N_d
    dist[start] = 0
    q = [(0, start)]
    while q:
        dist_v, v = heappop(q)
        if dist[v] != dist_v:
            continue
        for u, dist_vu in E[v]:
            dist_u = dist_v + dist_vu
            if dist_u < dist[u]:
                dist[u] = dist_u
                heappush(q, (dist_u, u))
    return dist


N, M = MAP()
L = [LIST() for i in range(M)]
graph = defaultdict(list)
for a, b in L:
    graph[a - 1].append((b - 1, 1))
    graph[b - 1].append((a - 1, 1))
ans = 0
for i in range(M):
    a, b = L[i]
    E = deepcopy(graph)
    E[a - 1].remove((b - 1, 1))
    E[b - 1].remove((a - 1, 1))
    dist = dijkstra(E, 0)
    if dist.count(INF) > 0:
        ans += 1
print(ans)

-from fractions import gcd -N, M = MAP() -L = [LIST() for i in range(M)] +N, M = MAP() +L = [LIST() for i in range(M)] -for a, b in L: +for i in range(M): +    a, b = L[i] -    d = dijkstra(E, a - 1) -    if d[b - 1] == INF: +    dist = dijkstra(E, 0) +    if dist.count(INF) > 0: