#include <fstream>
#include <vector>
#define NMAX 100005
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

int fv[NMAX],N,M,x,y,i,rasp;
vector<int> v[NMAX];

void dfs(int x)
    {
        unsigned int i;
        for(i=0;i<v[x].size();++i)
            if (!fv[v[x][i]])
                fv[v[x][i]]=1,dfs(v[x][i]);
    }

int main()
{
    f>>N>>M;
    while(M--)
        f>>x>>y,v[x].push_back(y),v[y].push_back(x);
    for(i=1;i<=N;++i)
        if (!fv[i])
            dfs(i),++rasp;
    g<<rasp;
    return 0;
}