#include <iostream>
#include <cstdio>
#include <vector>
using namespace std;
FILE* f=fopen("dfs.in","r");
FILE* g=fopen("dfs.out","w");
int n,m,x,y,k,viz[100001];
vector <int> v[100001];
void dfs(int s)
{
    viz[s]=1;
    for(int i=0;i<v[s].size();i++)
    {
        if(viz[v[s][i]]==0)
        {
            dfs(v[s][i]);
        }
    }
}
int main()
{
    fscanf(f,"%d%d",&n,&m);
    for(int i=0;i<m;i++)
    {
        fscanf(f,"%d%d",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1;i<=n;i++)
        if(!viz[i])
        {
            dfs(i);
            k++;
        }
    fprintf(g,"%d",k);
    return 0;
}