#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

#define nmax 100001

vector < int  > G[nmax];
int n,m,s,x,y,nr;
bitset<nmax> v;
int Nivel[nmax];
queue <int > q;


void dfs(int x)
{
    v[x]=1;
    for(int i=0;i<G[x].size();i++)
        if(v[G[x][i]]==0)
         dfs(G[x][i]);

}


int main()
{
    fin>>n>>m;
    while(m)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);

        m--;
    }


    for(int i=1;i<=n;i++)
    if(v[i]==0)
    {
        nr++;
        dfs(i);


    }

fout<<nr;




    return 0;
}