#include <fstream>
#include <bitset>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector<int> graf[100002];
int n,m,i,cc,x,y;
bool fr[100002];
void dfs(int start)
{
    fr[start]=1;
    for(auto i:graf[start])
        if(fr[i]==0)
            dfs(i);
}

int main()
{
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }
    cc=0;
    for(i=1;i<=n;i++)
    {
        if(fr[i]==0)
            dfs(i), cc++;
    }
    fout<<cc;
    return 0;
}