/**************************************************************

     Problem: 1006

     User: idy002

     Language: C++

     Result: Accepted

     Time:1672 ms

     Memory:11968 kb

 ****************************************************************/

 #include <cstdio>

 #include <vector>

 #define maxn 10010

 using namespace std;

 int n, m;

 vector<int> g[maxn];

 bool done[maxn];

 int label[maxn], pos[maxn];

 int msc() {

     int rt = ;

     for( int i=n; i>=; i-- ) {

         int mu = ;

         for( int u=; u<=n; u++ ) {

             if( !done[u] ) {

                 if( !mu || label[u]>label[mu] )

                     mu = u;

             }

         }

         done[mu] = true;

         pos[mu] = i;

         int cnt = ;

         for( int t=; t<g[mu].size(); t++ ) {

             int v = g[mu][t];

             if( done[v] ) {

                 cnt++;

             } else {

                 label[v]++;

             }

         }

         rt = max( rt, cnt+ );

     }

     return rt;

 }

 int main() {

     scanf( "%d%d", &n, &m );

     for( int i=,u,v; i<=m; i++ ) {

         scanf( "%d%d", &u, &v );

         g[u].push_back(v);

         g[v].push_back(u);

     }

     printf( "%d\n", msc() );

 }