#include <bits/stdc++.h>

using namespace std;

ifstream in ("dfs.in");
ofstream out ("dfs.out");

int a,b,g;
bool f[200001];
vector <int> v[100000];

void dfs (int e)
{
    f[e]=1;
    for(int i=0;i<v[e].size();i++)
    {
        if(f[v[e][i]]==0)
            dfs(v[e][i]);
    }
}

int main()
{
    in>>a>>b;
    for(int i=1;i<=b;i++)
    {
        int c,d;
        in>>c>>d;
        v[c].push_back(d);
        v[d].push_back(c);
    }
    for(int i=1;i<=a;i++)
        if(f[i]==0)
            g++,dfs(i);
    out<<g;
    return 0;
}