#include <iostream>
#include <cstdio>
#include <vector>
#include <queue>
using namespace std;
vector <int> lv[100000];
vector <int>::iterator it;
queue <int> corn;
int viz[100000];
int main()
{
    FILE *f=fopen("dfs.in","r");
    FILE *g=fopen("dfs.out","w");
    int i,n,m,x,y;
    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 cnx=0,nc,j;

    for(int j=1; j<=n; j++)
    {
        if(viz[j]==0)
        {
            cnx++;
            corn.push(j);
            while(!corn.empty())
            {
                nc=corn.front();
                corn.pop();
                for(it=lv[nc].begin(); it!=lv[nc].end(); ++it)
                {
                    if(viz[*it]==0)
                    {
                        viz[*it]=1;
                        corn.push(*it);

                    }

                }


            }





        }


    }
    fprintf(g,"%d",cnx);

    return 0;
}