#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

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

const int N = 100001;
vector <int> a[N];

int n, m, x, y, ans;
bool viz[100001];

void dfs(int x)
{
    viz[x] = true;
    for(auto y:a[x])
    {
        if(!viz[y])
            dfs(y);
    }
}


int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        a[x].push_back(y);
        a[y].push_back(x);
    }
    in.close();
    for(int i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            ans++;
            dfs(i);
        }
    }
    out<<ans;
    return 0;
}




/*



int n, m, x, y, a[1001][1001];
int ans, viz[1001];

void dfs(int nod)
{
    viz[nod] = ans;
    for(int i=1; i<=n; i++)
        if(a[nod][i] == 1 && viz[i] == 0)
            dfs(i);
}

int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        in>>x>>y;
        a[x][y] = a[y][x] = 1;
    }
    for(int i=1; i<=n; i++)
    {
        if(viz[i] == 0)
        {
            ans++;
            dfs(i);
        }
    }
    out<<ans;
    return 0;
}


*/