#include <iostream>
#include<bits/stdc++.h>

using namespace std;
int n,m,x,y,a,b,i,j,rad,cod,nr,ok,viz[100005];
vector<int>v[100005];
void radacina(int x)
{viz[x]=1;
    int j;

for(j=0; j<v[x].size(); j++)
        if(viz[v[x][j]]==0)radacina(v[x][j]);
}
ifstream f("dfs.in");
ofstream g("dfs.out");
int main()
{
    f>>n>>m;

    for(i=1; i<=m; i++)
    {
        f>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for(i=1; i<=n; i++)
        if(viz[i]==0)
        {
            radacina(i);
            nr++;
        }

    g<<nr;


}