#include <iostream>
#include<fstream>
#include<vector>
#define maxn 100005

using namespace std;
    ifstream fcin("dfs.in");
    ofstream fcout("dfs.out");

vector <int> v[maxn];
bool viz[maxn];

void dfs(int x)
{   int i;
    viz[x]=1;

    for(i=0; i<int(v[x].size()); i++)
        if(!viz[v[x][i]]) dfs(v[x][i]);
}

int main()
{   int n, m,nr=1, x, y, i;

    fcin>>n>>m;
    for(i=1; i<=m; i++)
    {   fcin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    dfs(1);
    for(i=1; i<=n; i++)
        if(!viz[i]) nr++, dfs(i);

    fcout<<nr;
    return 0;
}