#include <fstream>
#include <bitset>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
bitset< 100009 > viz;
vector<int>v[100009];
int n, m;
void dfs(int nod)
{
    viz[nod]=1;
    for(int i=0; i<v[nod].size(); i++)
        if(!viz[v[nod][i]]) dfs(v[nod][i]);
}
int main()
{
    in>>n>>m;
    for(int i=1; i<=m; i++)
    {
        int x,y;
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    int sum=0;
    for(int i=1; i<=n; i++)
        if( !viz[i] ) dfs(i), sum++;

out<<sum;
    return 0;
}