#include<fstream>
#include<vector>
using namespace std;ifstream f("dfs.in");ofstream g("dfs.out");vector<int>L[100001];int n,m,x,y,i,v[100001],nr;void adancime(int x)
{v[x]=1;for(int i=0;i<L[x].size();i++)if(v[L[x][i]]==0)adancime(L[x][i]);}int main(){f>>n>>m;for(i=1;i<=m;i++){f>>x>>y;L[x].push_back(y);L[y].push_back(x);}nr=0;for(i=1;i<=n;i++)if(v[i]==0){adancime(i);nr++;}g<<nr;return 0;}