#include <iostream>
#include <cstdio>
#include <vector>

using namespace std;

vector<int> a[100001];
int nr,viz[100001],n;

void df(int i)
{
    int j;
    viz[i]=nr;
    for (j=0;j<a[i].size();j++)
        if (viz[a[i][j]]==0) df(a[i][j]);
}

int main()
{
    int i,j,m,x,y;
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (i=1;i<=m;i++)
    {
        scanf("%d%d",&x,&y);
        a[x].push_back(y); a[y].push_back(x);
    }
   /* for(i=1;i<=n;i++)
    {
        printf("vecinii lui %d ",i);

        for(j=0;j<a[i].size();j++)
            printf("%d ",a[i][j]);
        printf("\n");
    }*/
    nr=0;
    for (i=1;i<=n;i++) if (viz[i]==0)
        {
            nr++;
            df(i);
        }
    printf("%d",nr);
    /*for (i=1;i<=nr;i++) { printf("\n");
        for (j=1;j<=n;j++) if (viz[j]==i) printf("%d ",j);}*/
    return 0;
}