#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

vector <int> lv[100010];
int filled[100010];
void DFS(int nc)
{
    filled[nc]=1;
    vector <int>::iterator ii;
    for(ii=lv[nc].begin();ii!=lv[nc].end();++ii)
    {
        if(!filled[*ii])
            DFS(*ii);
    }

}



int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    int n,m;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;i++)
    {
        int x,y;
        scanf("%d%d",&x,&y);
        lv[x].push_back(y);
        lv[y].push_back(x);
    }
    int k=0;
    for(int i=1;i<=n;i++)
    {
        if(!filled[i])
        {
            k++;
            DFS(i);
        }
    }
    printf("%d",k);
    return 0;
}