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#include "sabotaz.h"
#include "message.h"

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstring>
#include <vector>
#include <set>
#include <map>
#include <cmath>
#include <list>
#include <ctime>
#include <sstream>
#include <queue>
#include <stack>
#include <bitset>
#include <unordered_set>
#include <unordered_map>
using namespace std;
typedef vector<int> vi;
typedef pair<int,int> pii;
typedef long long ll;
typedef unsigned long long ull;
typedef short int sint;
#define FOR(x, b, e) for(int x=(b); x<=(e); ++x)
#define FORD(x, b, e) for(int x=((int)(b))-1; x>=(e); --x)
#define REP(x, n) for(int x=0; x<(n); ++x)
#define ALL(c) c.begin(),c.end()
#define SIZE(x) ((int)((x).size()))
#define PB push_back
#define ST first
#define ND second
#define mp(x,y) make_pair(x,y)
#define DEBUG 1
#define debug(x) {if (DEBUG)cerr <<#x <<" = " <<x <<endl; }
#define debugv(x) {if (DEBUG) {cerr <<#x <<" = "; FOREACH(it, (x)) cerr <<*it <<", "; cout <<endl; }}
#define REMAX(a,b) (a)=max((a),(b));
#define REMIN(a,b) (a)=min((a),(b));
#define wez(n) int (n); scanf("%d",&(n));
#define wez2(n,m) int (n),(m); scanf("%d %d",&(n),&(m));

using namespace std;

const int N = 202010;
vi za[N];
int parent[N];
int low[N], disc[N];
bool visited[N];
int czas;
int res;

void gogo(int u) {
	visited[u] = true;
	disc[u] = low[u] = ++czas;
	for (auto v : za[u]) {
		if (!visited[v]) {
			parent[v] = u;
			gogo(v);
			low[u] = min(low[u], low[v]);
			if (low[v] > disc[u]) {
				++res;
			}
		} else if (v != parent[u]) {
			low[u] = min(low[u], disc[v]);
		}
	}
}

int main() {
  if (MyNodeId() != 0) { 
    return 0;
  }

  long long N = NumberOfIsles();
  long long M = NumberOfBridges();
  REP(i, M) {
  	int x = BridgeEndA(i);
  	int y = BridgeEndB(i);
  	za[x].PB(y);
  	za[y].PB(x);
  }
  FOR(i, 1, N) {
  	if (!visited[i]) {
  		gogo(i);
  	}
  }
  printf("%d\n", res);
 
  return 0;
}