#include <cstdio>
#include <vector>
#define nmax 100005

using namespace std;

int n,m,nr,viz[nmax];
vector<int> g[nmax];

void citire()
{
    int a,b;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        scanf("%d%d",&a,&b);
        g[a].push_back(b);
        g[b].push_back(a);
    }
}

void dfs(int k)
{
    viz[k]=1;
    for(vector<int>::iterator ii=g[k].begin();ii!=g[k].end();++ii)
        if(viz[*ii]==0)
            dfs(*ii);
}

void rezolv()
{
    for(int i=1;i<=n;i++)
    {
        if(viz[i]==0)
        {
            nr++;
            dfs(i);
        }
    }
}

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