#include<cstdio>
#include<vector>
#define MAX 100003
using namespace std;
vector<int> v[MAX];
bool viz[MAX];
 void dfs(int nod)
 {
     viz[nod]=1;
     for(int i=0;i<v[nod].size();i++)
     {

        if(viz[v[nod][i]]==0)
            dfs(v[nod][i]);
     }
 }
 int main()
 {
     int n,m,cnt=0;
     FILE *fin,*fout;
     fin=fopen("dfs.in","r");
     fout=fopen("dfs.out","w");
     fscanf(fin,"%d%d",&n,&m);
     for(int i = 1; i <= m; i++)
    {
        int x, y;
        fscanf(fin, "%d %d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=0;i<n;i++)
    {
        if(viz[i]==0)
        {
            cnt++;
            dfs(i);
        }
    }
    fprintf(fout,"%d",cnt);
 }