#include<stdio.h>
#include<vector>
using namespace std;
vector<int> v[100005];bool viz[100005];
void dfs(int u)
{
    viz[u]=true;
    for(vector<int>::iterator it=v[u].begin();it!=v[u].end();it++)
        if(viz[*it]==0)
            dfs(*it);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m,i,a,b;
    scanf("%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        scanf("%d%d",&a,&b);
        v[a].push_back(b);
        v[b].push_back(a);
    }
    int nr=0;
    for(i=1;i<=n;i++)
        if(viz[i]==false)
            {
                nr++;
                dfs(i);
            }
    printf("%d\n",nr);
    return 0;
}