#include<bits/stdc++.h>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector<int>v[100005];

int compconex[100005];
int viz[100005];

int n,m,k,x,y;

void dfs(int val)
{
    int i;
    viz[val]=1;
    compconex[val]=k;
    for(i=0;i<v[val].size();i++)
        if(viz[v[val][i]]==0)
             dfs(v[val][i]);
}
int main()
{
    int i;
    fin>>n>>m;
    for(i=1;i<=m;i++)
    {
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(i=1;i<=n;i++)
        if(viz[i]==0)
        {
            dfs(i);
            k++;
        }
    fout<<k;
    return 0;
}