#include<fstream>
#include<vector>
#define nx 100007
using namespace std;
int viz[nx],n,m,i,x,y,k;
vector<int>v[nx];

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

void dfs(int x)
{
    viz[x]=1;
    for(int j=0;j<v[x].size();j++)if(!viz[v[x][j]])dfs(v[x][j]);
}

int main()
{
    fin>>n>>m;

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

    for(i=1;i<=n;i++)if(!viz[i])dfs(i),k++;
    fout<<k;
    return 0;
}