#include <stdio.h>
#include <stdlib.h>
#include <vector>

using namespace std;

vector <int> v[100000];
int         ok[100000];

void dfs(int nod){
    ok[nod]++;
    for(int i=0;i<v[nod].size();i++){
        if(ok[v[nod][i]==0)
            dfs(v[nod][i]);
    }
}

int main()
{
    FILE *fin, *fout;
    int n,m,i,j;
    fin=fopen("dfs.in","r");
    fout=fopen("dfs.out","w");
    fscanf(fin,"%d%d",&n,&m);
    for(m;m>0;m--){
        fscanf(fin,"%d%d",&i,&j);
        v[i].push_back(j);
        v[j].push_back(i);
    }
    int sol=0;
    for(i=0;i<n;i++){
        if(ok[i]==0){
            dfs(i);
            sol++;
        }
    }
    fprintf(fout,"%d",sol);
    fclose(fin);
    fclose(fout);
    return 0;
}