#include <iostream>
#include <fstream>
using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
int a[1005][1005], n, m,x,y, viz[1005], cnt;



void DFS1(int nod)
{
    int i;
    viz[nod] = 1;
    for (i = 1; i <= n; i++)
        if (viz[i]==0 && a[nod][i]==1)
            DFS1(i);
}



void DFS(int nod)
{
    int i;
    viz[nod]=1;
    for(i=1;i<=n;i++)
    {
        if(viz[i]==0 and a[nod][i]==1)
            DFS(i);
    }
}
int main()
{
        fin>>n>>m;
    for(int i=1;i<=m;i++){
        fin>>x>>y;
        a[x][y]=a[y][x]=1;
    }

    int i;
    for (i = 1; i <= n; i++)
        if (viz[i]==0)
         {
            cnt++;
            DFS(i);
        }
    fout<<cnt;
    return 0;
}