#include <bits/stdc++.h>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int n, m, a[10005][10005];
bool viz[100005];

void dfs(int nod)
{
    viz[nod] = true;
    for(int i = 1; i <= n; i++)
    {
        if(a[nod][i] == 1 && viz[i] == false)
        {
           dfs(i);
        }
    }
}

int main()
{
    int ct = 0, x ,y ;
    in >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        in >> x >> y;
        a[x][y] = 1;
        a[y][x] = 1;
    }
    for(int i = 1 ; i <= n; i++)
    {
        if(viz[i] == false)
        {
            ct++;
            dfs(i);
        }
    }
    out << ct;

    return 0;
}