#include <fstream>
#include <vector>
using namespace std;

ifstream cin("dfs.in");
ofstream cout("dfs.out");

const int nmax=100001;
int k=0;

void citire(vector<int> G[],int &N,int &M)
{
    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);
    }
}
void DFS(vector<int>G[],int nod,bool V[])
{
    V[nod]=true;
    for(int i=0; i<G[nod].size(); i++)
        if(V[G[nod][i]]==false){
            DFS(G,G[nod][i],V);
            k++;
        }
}
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<<k+1;
    return 0;
}