#include <bits/stdc++.h>
using namespace std;
ifstream fin ("dfs.in");
ofstream fout("dfs.out");
int n,m;
vector<int>v[100002];
bool viz[100002];


void dfs (int k)
{
    viz[k]=1;
    for (auto x:v[k])
        if (viz[x]==0)
            dfs (x);
}


int main()
{
    fin>>n>>m;
    int x,y,i,k=0;
    for (i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i=1;i<=n;i++)
    if (viz[i]==0)
    {
        dfs(i);
        ++k;
    }
    fout<<k;
    return 0;
}