import java.io.*;
import java.util.*;

public class Main {
    static InputStream is;
    static PrintWriter out;
    static String INPUT = "";

    static long MODULO = 1_000_000_000 + 7;
    static long[] fac = new long[200000];
    static long[] invfac = new long[200000];
    static long[] inv = new long[200000];
    
    static void solve()
    {
        int n = ni();
        int m = ni();
        int[] a = new int[m];
        int[] b = new int[m];
        for(int i = 0; i < m; i++){
            a[i] = ni()-1;
            b[i] = ni()-1;
        }
        int res = 0;
        for(int i = 0; i < m; i++){
            UnionFind map = new UnionFind(n);
            for(int j = 0; j < m; j++){
                if(j == i) continue;
                map.union(a[j],b[j]);
            }
            res += map.count(n)-1;
        }
        out.println(res);

    }

    public static class UnionFind{  
        int parent[];
        int rank[];
        
        public UnionFind(int n){
            parent = new int[n];
            rank   = new int[n];
            
            for(int i = 0;i < n;i++){
                parent[i] = i;
                rank[i]   = 0;
            }        
        }
        
        boolean same(int x,int y){
            return find(x) == find(y);
        }
        
        public int find(int x){
            if(parent[x] == x){
               return x;
            }else{
               return parent[x] = find(parent[x]);   
            }        
        }
          
        public void union(int x,int y){
            x = find(x);
            y = find(y);
            
            if(x != y){
                if(rank[x] > rank[y]){
                   parent[y] = x; 
                }else{
                   parent[x] = y;
                   if(rank[x] == rank[y]){
                       rank[y]++;
                   }
                }            
            }
            
            return;
        }
        
        public int count(int n){
            int ret = 0;
            for(int i = 0;i < n;i++){
                if(i == find(i)){
                    ret++;
                }
            }
            return ret;
        }
          
      } 


    public static void main(String[] args) throws Exception
    {
        long S = System.currentTimeMillis();
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);
        
        solve();
        out.flush();
        long G = System.currentTimeMillis();
        tr(G-S+"ms");
    }

    
    private static boolean eof()
    {
        if(lenbuf == -1)return true;
        int lptr = ptrbuf;
        while(lptr < lenbuf)if(!isSpaceChar(inbuf[lptr++]))return false;
        
        try {
            is.mark(1000);
            while(true){
                int b = is.read();
                if(b == -1){
                    is.reset();
                    return true;
                }else if(!isSpaceChar(b)){
                    is.reset();
                    return false;
                }
            }
        } catch (IOException e) {
            return true;
        }
    }
    
    private static byte[] inbuf = new byte[1024];
    static int lenbuf = 0, ptrbuf = 0;
    
    private static int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }
    
    private static boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
//  private static boolean isSpaceChar(int c) { return !(c >= 32 && c <= 126); }
    private static int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
    
    private static double nd() { return Double.parseDouble(ns()); }
    private static char nc() { return (char)skip(); }
    
    private static String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b))){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    
    private static char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }
    
    private static char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }
    
    private static int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }
    
    private static int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private static long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private static void tr(Object... o) { if(INPUT.length() != 0)System.out.println(Arrays.deepToString(o)); }

    private static int[] nsi(){
        char[] s = ns().toCharArray();
        int[] a = new int[s.length];
        for(int j = 0; j < s.length; j++){
           a[j] = s[j] - '0';
        }
        return a;
    }
}

Measured memory_bytes: 27220