#include<iostream>
#include<fstream>
#include<stdio.h>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,i,j,a[1000][1000],x,y,v[1000],k;
void DFS(int nod)
{
    int i;
    v[nod] = 1;
    for (i = 1; i <= n; i++)
        if (v[i]==0 && a[nod][i])
            DFS(i);
}
int main()
{
    f>>n>>m;
    for(j=1;j<=m;j++)
        {
            f>>x>>y;
            a[x][y]=1;
            a[y][x]=1;
        }
    for (i = 1; i <= n; i++)
        if (!v[i])
        {
            k++;
            DFS(i);
        }
        g<<k;
    return 0;
}