#include <iostream>
#include <cstdio>
#include <queue>
#include <vector>
using namespace std;
FILE *f=fopen("dfs.in","r");
queue <int> q;
vector <int> lv[100009];
int n,m;
int used[100009];
void dfs(int nc)
{
    used[nc]=1;
    vector <int> ::iterator ii;
    for(ii=lv[nc].begin();ii!=lv[nc].end();ii++)
    {
        if(!used[*ii])
            dfs(*ii);
    }
}
int main()
{
    int x,y,i;
    fscanf(f,"%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        fscanf(f,"%d%d",&x,&y);
        lv[x].push_back(y);
        lv[y].push_back(x);
    }
    int ncc=0;
    for(i=1;i<=n;i++)
    {
        if(!used[i])
        {
            dfs(i);
            ncc++;
        }
    }
    fclose(f);
    f=fopen("dfs.out","w");
    fprintf(f,"%d",ncc);
    return 0;
}