#include <bits/stdc++.h>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector<int> ls[100001];
int i,j,m,n,s,x,y,d[100001];

void dfs (int x)
{
    d[x]=1;
    for (int i=0;i<ls[x].size();i++)
     if (d[ls[x][i]]==0)  dfs(ls[x][i]);
    return ;
}
int main()
{
    fin>>n>>m;
    for (i=1;i<=m;i++)
    {
        fin>>x>>y;
        ls[x].push_back(y);
        ls[y].push_back(x);
    }
    for (i=1;i<=n;i++)
     if (d[i]==0) {s++; dfs(i);}
     fout<<s;
    return 0;
}