#include <iostream>
#include <fstream>
#include <vector>
#include <list>

using namespace std;
list <int> *v;
vector <bool> viz;
void dfs(int x)
{viz[x]=true;
for(list<int>::iterator i=v[x].begin();i!=v[x].end();i++)if(!viz[*i])dfs(*i);
}
ifstream fin("dfs.in");
ofstream fout("dfs.out");

int main()
{int n,m,x,y,i;
    fin>>n>>m;
    v=new list<int>[n+1];
    viz.resize(n+1,0);
    while(m--)
    {fin>>x>>y;
     v[x].push_back(y);
     v[y].push_back(x);
    }

    int nrc=0;
    for(i=1;i<=n;i++)if(!viz[i]){dfs(i);nrc++;}
    fout<<nrc;
}