#include <iostream>
#include <vector>
#include <fstream>
#define nri 100008

using namespace std;

vector <int>L[nri];

int V[nri];

int m,n,q;

ofstream fout("dfs.out");

ifstream fin("dfs.in");

void Citire()
{
int i ,x,y;
fin>>n>>m;
for(i=1;i<=m;i++)
{
fin>>x>>y;
L[x].push_back(y);
L[y].push_back(x);

}
}

void dfs(int x)
{
    if(V[x]==0)
    {
        V[x]=1;
        for(int unsigned i = 0 ; i < L[x].size();i++)
            dfs(L[x][i]);
    }
}
int main()
{
    Citire();
    for(int i=1;i<=n;i++)
        if(V[i]==0)
        {
            q++;
            dfs(i);
        }

    fout<<q;

    return 0;
}