#include <fstream>
#include <vector>
#include <iostream>
using namespace std;
const int nmax=101;
int cnt;
ofstream fout("dfs.out");
void citire(vector<int> G[],int &N,int &M)
{
ifstream fin("dfs.in");
cin>>N>>M;
int x,y;
for(int i=1;i<=M;i++)
{
cin>>x>>y;
G[x].push_back(y);
G[y].push_back(x);
}
fin.close();
}
void DFS(vector<int>G[],int nod,bool V[])
{
V[nod]=true;
cnt++;
for(int i=0;i<G[nod].size();i++)
if(V[G[nod][i]]==false) DFS(G,G[nod][i],V);
}
int main()
{
int N,M;
bool V[nmax];
vector <int> G[nmax];
citire(G,N,M);
for(int i=1;i<=N;++i)
V[i]=false;
DFS(G,1,V);
cout<<cnt;
return 0;
}