#include<iostream>
#include<vector>
#include<fstream>
#define maxn 100005

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

vector <int> t[maxn];
int i,j,n,m,nod[maxn],comp;

void dfs(int k)
        {
        nod[k]=1;
        for(int j=0;j<t[k].size();j++)
        if(nod[t[k][j]]==0)dfs(t[k][j]);
        }

int main()
{
f>>n>>m;
while(m>0)
        {
        f>>i>>j;
        t[i].push_back(j);
        t[j].push_back(i);
        m--;
        }
comp=0;
for(i=1;i<=n;i++)if(nod[i]==0){dfs(i);comp++;}
g<<comp;
g.close();
return 0;
}