#include <cstdio>
#include <vector>
using namespace std;

vector <int> lv[100001];
int used[100001];

void dfs(int nc)
{
    used[nc]=1;
    vector<int>::iterator i;
    for(i=lv[nc].begin();i!=lv[nc].end();++i)
        if(!used[*i])
                dfs(*i);
}

int main()
{
    int n,m,x,y,i;
    FILE *f=fopen("dfs.in","r");
    fscanf(f,"%d%d",&n,&m);
    for(i=1;i<=m;i++)
    {
        fscanf(f,"%d%d",&x,&y);
        lv[x].push_back(y);
        lv[y].push_back(x);
    }
    int ncc=0;
    for(i=1;i<=n;i++)
        if(!used[i])
        {
            dfs(i);
            ncc++;
        }
    fclose(f);
    f=fopen("dfs.out","w");
    fprintf(f,"%d",ncc);
    return 0;
}