#include <iostream>
#include <fstream>

using namespace std;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");

int n, i, j, m, nr;
int a[2][400010];
int viz[100010], k;
int start[100010];
int nodc, ans;


void dfs(int nod)
{
    viz[nod] = 1;
    int i = start[nod];
    while(i!=0)
    {
        nodc = a[0][i];
        i = a[1][i];
        if (viz[nodc] == 0)
            dfs(nodc);
    }
    
}

int main()
{
    fin >> n >> m;
    for (int z=1; z<=m; z++)
    {
        fin >> i >> j;
        
        k++;
        a[0][k] = j;
        a[1][k] = start[i];
        start[i] = k;
        
        k++;
        a[0][k] = i;
        a[1][k] = start[j];
        start[j] = k;
        
    }
    for (int i=1; i<=n; i++)
    {
        if (viz[i] == 0)
        {
            dfs(i);
            ans++;
        }
    }
    fout << ans;
    
         
}