#include<bits/stdc++.h>
#define mod 1000000007
using namespace std;
ifstream fin("dfs.in");
ofstream g("dfs.out");
vector<int>a[100002];
bool viz[100002];

void dfs(int x)
{
    viz[x]=1;
    for(int i=0;i<a[x].size();i++)
        if(viz[a[x][i]]==0)
            dfs(a[x][i]);

}


int main()
{
    int n,m,x,y,ct=0,i;
    fin>>n>>m;
    for(int k=1;k<=m;k++)
    {
        fin>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(viz[i]==0)
    {
        ct++;
        dfs(i);
    }
        g<<ct;

    return 0;
}