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

using namespace std;

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

void read()
{
    int a,b;
    scanf("%d%d",&n,&m);
    for(int i=1;i<=m;++i)
    {
        scanf("%d%d",&a,&b);
        g[a].push_back(b);
        g[b].push_back(a);
    }
}

void dfs(int k)
{
    viz[k]=1;
    for(vector<int>::iterator it=g[k].begin();it!=g[k].end();++it)
        if(!viz[*it])
            dfs(*it);
}

void solve()
{
    int ncc=0;
    for(int i=1;i<=n;++i)
        if(!viz[i])
        {
            ++ncc;
            dfs(i);
        }
    printf("%d\n",ncc);
}

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