1 #include<bits/stdc++.h>
2 #define LL long long
3 #define fi first
4 #define se second
5 #define mk make_pair
6 #define pii pair<int,int>
7
8 using namespace std;
9
10 const int N=2000+7;
11 const int M=1e4+7;
12 const int inf=0x3f3f3f3f;
13 const LL INF=0x3f3f3f3f3f3f3f3f;
14 const int mod=1e9 + 7;
15
16 int n, m, vis[N], match[N];
17 bool edge[N][N];
18
19 int path(int u) {
20 for(int v = 1; v <= n; v++) {
21 if(edge[u][v] && !vis[v]) {
22 vis[v] = 1;
23 if(match[v] == -1 || path(match[v])) {
24 match[v] = u;
25 return 1;
26 }
27 }
28 }
29 return 0;
30 }
31
32 int main() {
33 memset(match, -1, sizeof(match));
34 scanf("%d%d", &n, &m);
35 for(int i = 1; i <= m; i++) {
36 int x, y; scanf("%d%d", &x, &y);
37 x++, y++;
38 edge[i][x] = edge[i][y] = 1;
39 }
40 int ans = 0;
41 for(int i = 1; i <= m; i++) {
42 memset(vis, 0, sizeof(vis));
43 if(path(i)) ans++;
44 else break;
45 }
46 printf("%d\n", ans);
47 return 0;
48 }
