#include <iostream>
#include <vector>
#include<fstream>
using namespace std;

vector <int> graph[100005];
int viz[100005];
int nrc=0;

void dfs(int x)
{
    viz[x]=1;
    int i,lim=graph[x].size();
    for(i=0;i<lim;i++) {
        int vecin = graph[x][i];
        if(viz[vecin] == 0)
            dfs(vecin);
    }
}
int main()
{ ifstream f("dfs.in");
ofstream g("dfs.out");
    int N,M,x,y;
f>>N>>M;
int i;
for(i=1;i<=M;i++)
{
    f>>x>>y;
    graph[x].push_back(y);
    graph[y].push_back(x);
}
for (i=1;i<=N;i++)
{
    if(viz[i]==0)
    {
        dfs(i);
        nrc++;
    }
}
g<<nrc<<endl;
g.close();
f.close();
    return 0;
}