#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <vector>
#include <algorithm>
#include <stack>
#include <queue>
#include <math.h>
#include <string.h>
#include <set>
#include <map>
#include <iostream>
#include <sstream>
#define MAXN 103
#define ll long long int
#define INF 0x3f3f3f3f
#define PI acos(-1)
#define MOD 1000000007LL

using namespace std;

int n, m, U, V, deg[MAXN], vis[MAXN];
bool dp[MAXN][MAXN];
bool can;
vector<vector<int> > g(MAXN);

void dfs(int u, int father, int begin){
	if(can) return;
	vis[u] = 1;
	for(int i = 0; i < g[u].size(); i++){
		int next = g[u][i];
		if(next == begin && father != begin){
			can = 1;
			break;
		}else{
			if(!vis[next]){
				dfs(next, u, begin);
			}
		}
	}
}

int main(){
	while(scanf("%d%d", &n, &m) && n > -1 && m > -1){
		memset(deg, 0, sizeof(deg));
		for(int i = 1; i <= n; i++){
			g[i].clear();
			vis[i] = 0;
		}
		for(int i = 0; i < m; i++){
			scanf("%d%d", &U, &V);
			g[U].push_back(V);
			g[V].push_back(U);
			deg[U]++;
			deg[V]++;
		}
		bool go = true;
		int ans = 0;
		while(go){
			go = false;
			int idxA = -1, idxB = -1;
			for(int j = 1; j <= n; j++){
				if(deg[j] < 2){
					idxA = j;
					break;
				}
			}
			for(int j = 1; j <= n; j++){
				if(deg[j] < 2 && idxA != j){
					idxB = j;
					break;
				}
			}
			if(idxA == -1 && idxB == -1){
				break;
			}
			if(idxA != -1){
				deg[idxA]++;
				go = 1;
			}
			if(idxB != -1){
				deg[idxB]++;
				go = 1;
			}else{
				if(idxA != -1){
					if(deg[idxA] < 2){
						deg[idxA]++;
					}
				}
			}
			ans++;
		}
		vector<int> candidate;
		if(ans == 0){
			for(int i = 1; i <= n; i++){
				memset(vis,0,sizeof(vis));
				if(!vis[i]){
					can = 0;
					dfs(i, -1, i);
					if(!can){

						candidate.push_back(i);
					}
				}
			}
		}
		printf("%d\n", ans + ((int)candidate.size()+1) / 2 );
	}
	return 0;
}