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

#define NMax 100005

ifstream f("dfs.in");
ofstream g("dfs.out");

int n,m,sol;
int viz[NMax];
vector<int> v[NMax];
queue<int> cd;

void DFS(int s)
{
    int i;
    cd.push(s);
    viz[s]=1;
    while(!cd.empty())
    {
        s=cd.front();
        cd.pop();
        viz[s]=1;
        for(i=0;i<v[s].size();++i) if(!viz[v[s][i]]) cd.push(v[s][i]);
    }
}

int main()
{
    int i,a,b;

    f>>n>>m;
    for(i=1;i<=m;++i)
    {
        f>>a>>b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

    for(i=1;i<=n;++i) if(!viz[i]) {DFS(i);sol++;}

    g<<sol<<"\n";

    f.close();
    g.close();
    return 0;
}