#include <cstdio>
#include <iostream>
#include <vector>
#define NMAX 100000+5
using namespace std;

int N,M;
vector<int> m[NMAX];
bool c[NMAX];

void dfs(int nod)
{
    c[nod]=true;
        for(int i=0;i<m[nod].size();i++)
            if(c[m[nod][i]]==false)
                dfs(m[nod][i]);
}

int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d",&N,&M);
    for(int i=1;i<=M;i++)
    {
        int x,y;
        scanf("%d %d",&x,&y);
        m[x].push_back(y);
        m[y].push_back(x);
    }

    int ans=0;
    for(int i=1;i<=N;i++)
    {
        if(c[i]==false)
        {
            ans++;
            dfs(i);
        }
        else continue;
    }

    printf("%d",ans);

    return 0;
}