#include <iostream>
#include <cstdio>
#include <cstring>
#include <vector>
#define NMAX 100005

using namespace std;

vector<int>G[NMAX];
int viz[NMAX];
int n, m;
int rez;

void dfs(int nr)
{
    viz[nr] = 1;
    vector<int> ::iterator it;
    for (it = G[nr].begin(); it!=G[nr].end(); it++)
    {
        if (viz[*it] == 0)
            dfs(*it);
    }
}
void solve()
{
    for(int i=1; i<=n; i++)
    {
        if (viz[i] == 0)
        {
            dfs(i);
            rez++;
        }
    }

    printf("%d", rez);
}
void read()
{
    int x, y;
    scanf("%d %d\n", &n, &m);

    for (int i=0; i<m; i++)
    {
        scanf("%d %d\n", &x, &y);
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    read();
    solve();
    return 0;
}