#include <stdio.h>
#include <stdlib.h>
int n,m,*a[100001],i,comp,x,y,;
char viz[100001];
void dfs(int x)
{
    viz[x]=1;
    for(i=1; i<=a[x][0]; i++)
     if(!viz[a[x][i]]) dfs(a[x][i]);
}
int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);
    scanf("%d %d",&n,&m);
    for(i=1; i<=n; i++)
    {
        a[i]=(int *)realloc(a[i],sizeof(int));
        a[i][0]=0;

    }
    for(i=0; i<m; i++)
    {
        scanf("%d %d",&x,&y);
        a[x][0]++;
        a[x]=(int *)realloc(a[x],(a[x][0]+1)*sizeof(int));
        a[x][a[x][0]]=y;
        a[y][0]++;
        a[y]=(int *)realloc(a[y],(a[y][0]+1)*sizeof(int));
        a[y][a[y][0]]=x;
    }
    for(i=1; i<=n; i++)
     if(!viz[i])
      {
          comp++;
          dfs(i);
      }
    printf("%d",comp);
    return 0;
}