#include <iostream>
#include <cstdio>
#include <vector>
const int NMAX = 100003;
using namespace std;
int n,m,r;
vector<int> graf[NMAX];
bool viz[NMAX];
void dfs(int snod)
{
    viz[snod]=1;
    int leg=graf[snod].size();
    for(int i=0; i<leg; i++)
    {
        int nod=graf[snod][i];
        if(!viz[nod])
        {
            dfs(nod);
        }
    }
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d", &n,&m);
    int x,y;
    for(int i=0; i<m; i++)
    {
        scanf("%d %d", &x,&y);
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            r++;
            dfs(i);
        }
    }
    cout<<r;
    return 0;
}