#include <bits/stdc++.h>

using namespace std;

vector <int > g[100005];
int n,m,viz[100005];
void citire()
{
    scanf("%d%d",&n,&m);
    for (int i=1;i<=m;++i)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        g[x].push_back(y);
        g[y].push_back(x);
    }
}
void dfs(int nod)
{
    viz[nod]=1;
    for (vector <int > :: iterator it=g[nod].begin();it!=g[nod].end();++it)
        if (!viz[*it])
            dfs(*it);
}
int solve()
{
    int sol=0;
    for (int i=1;i<=n;++i)
        if(viz[i]==0)
    {
        dfs(i);
        ++sol;
    }
    return sol;
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    citire();
    printf("%d ",solve());
    return 0;
}