#include <fstream>
#include <cstring>
#include <vector>

#define X1 100001

using namespace std;

ifstream in;
ofstream out;

vector <int> v[X1];
int use[X1];

inline void df(int nod)
{
    use[nod]=1;
    for(vector <int>::iterator it=v[nod].begin();it!=v[nod].end();++it)
        if(!use[*it]) df(*it);
}

int main()
{
    int M,N,x,y,cnt;

    in.open("dfs.in");
    in>>N>>M;
    for(;M;--M)
    {
        in>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    in.close();

    memset(use,0,sizeof(use));
    cnt=0;

    for(int i=1;i<=N;++i)
        if(!use[i]) df(i),++cnt;

    out.open("dfs.out");
    out<<cnt<<'\n';
    out.close();

    return 0;
}