#include<cstdio>
#include<vector>
using namespace std;
FILE*in=fopen("dfs.in","r");
FILE*out=fopen("dfs.out","w");
int N,M,i,a,b,ct;
bool viz[100002];
vector <int> v[100002];
void DFS(int n)
{
    viz[n]=1;
    for(int j=0;j<v[n].size();j++)
    {
        int vec=v[n][j];
        if(viz[vec]==0)
        {
            DFS(vec);
        }
    }
}
int main()
{
    fscanf(in,"%d%d",&N,&M);
    for(i=1;i<=M;i++)
    {
        fscanf(in,"%d%d",&a,&b);
        v[a].push_back(b);
        v[b].push_back(a);
    }
    for(i=1;i<=N;i++)
    {
        if(viz[i]==0)
        {
            ct++;
            DFS(i);
        }
    }
    fprintf(out,"%d",ct);
}