#include<fstream>
#include<vector>

using namespace std;

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

const int NMAX = 100001;

vector <int> g[NMAX];

int V[NMAX],CP=0,N,M,i;

void df(int x)
{
    int i;
    V[x]=1;
    for (i=0;i<g[x].size();i++)
        if (!V[ g[x][i] ])
          df(g[x][i]);
}

int main()
{
    cin>>N>>M;
    while (M--)
    {
        int x,y;
        cin>>x>>y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for (i=1;i<=N;i++)
        if (!V[i]) CP++, df(i);
    cout<<CP;
    return 0;
}