#include <iostream>
#include <fstream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> v[100005];
queue <int> q;
int i,n,m,s,x,y,nr,viz[100005];
void dfs(int s)
{viz[s]=1;
for(int i:v[s])
    {if(!viz[i])
        dfs(i);
    }
}
int main()
{f>>n>>m;
for(i=1;i<=m;i++)
    {f>>x>>y;
    v[x].push_back(y);
    v[y].push_back(x);
    }
sort(v[i].begin(),v[i].end());
for(i=1;i<=n;i++)
    if(!viz[i])nr++,dfs(i);
g<<nr;
    
}