#include <fstream>
#include <vector>
#include <algorithm>

using namespace std;

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

const int NMAX = 100005;
vector<int>G[NMAX];
int viz[NMAX];

void dfs(int nod)
{
    viz[nod] = 1;
    for(auto x : G[nod])
        if(!viz[x])
            dfs(x);
}

int n,m,cc;

int main()
{
    int i,x,y;
    fin >> n >> m;
    for(i=1;i<=m;++i)
    {
        fin >> x >> y;
        if(find(G[x].begin(),G[x].end(),y) == G[x].end())
        {
            G[x].push_back(y);
            G[y].push_back(x);
        }
    }
    for(i=1;i<=n;++i)
        if(!viz[i])
        {
            cc++;
            dfs(i);
        }

    fout << cc << '\n';
    return 0;
}