#include <stdio.h>
int v[1001][1001],n,uz[1000];
void citire(){
    freopen("dfs.in","r",stdin);
    int m,x,y,i;
    scanf("%d %d",&n,&m);
    for(i=1;i<=m;i++){
        scanf("%d %d",&x,&y);
        v[x][++v[x][0]]=y;
        v[y][++v[y][0]]=x;
    }
    fclose(stdin);
}
void dfs(int k){
    int i;
    uz[k]=1;
    for(i=1;i<=v[k][0];i++)
      if(!uz[v[k][i]])dfs(v[k][i]);

}
int main(){
freopen("dfs.out","w",stdout);
citire();
int c,i;
c=0;
for(i=1;i<=n;i++)
    if(!uz[i])
    {
    dfs(i);
    c++;
    }
printf("%d",c);
fclose(stdout);
return 0;
}