import std.algorithm, std.container, std.conv, std.math, std.range, std.typecons, std.stdio, std.string;

void readV(T...)(ref T t){auto r=readln.splitter;foreach(ref v;t){v=r.front.to!(typeof(v));r.popFront;}}
void readC(T...)(size_t n,ref T t){foreach(ref v;t)v=new typeof(v)(n);foreach(i;0..n){auto r=readln.splitter;foreach(ref v;t){v[i]=r.front.to!(ElementType!(typeof(v)));r.popFront;}}}

void main()
{
  int n, m; readV(n, m);
  int[] a, b; readC(m, a, b);
  a[] -= 1; b[] -= 1;

  auto r = 0;
  foreach (i; 0..m) {
    auto uf = UnionFind!int(n);
    foreach (j; 0..m)
      if (i != j) uf.unite(a[j], b[j]);
    if (uf.countForests > 1) ++r;
  }

  writeln(r);
}

struct UnionFind(T)
{
  import std.algorithm, std.range;

  T[] p; // parent
  const T s; // sentinel
  const T n;
  T countForests; // number of forests
  T[] countNodes; // number of nodes in forests

  this(T n)
  {
    this.n = n;
    s = n;
    p = new T[](n);
    p[] = s;
    countForests = n;
    countNodes = new T[](n);
    countNodes[] = 1;
  }

  T opIndex(T i)
  {
    if (p[i] == s) {
      return i;
    } else {
      p[i] = this[p[i]];
      return p[i];
    }
  }

  bool unite(T i, T j)
  {
    auto pi = this[i], pj = this[j];
    if (pi != pj) {
      p[pj] = pi;
      --countForests;
      countNodes[pi] += countNodes[pj];
      return true;
    } else {
      return false;
    }
  }

  auto countNodesOf(T i) { return countNodes[this[i]]; }
  bool isSame(T i, T j) { return this[i] == this[j]; }

  auto groups()
  {
    auto g = new T[][](n);
    foreach (i; 0..n) g[this[i]] ~= i;
    return g.filter!(l => !l.empty);
  }
}
