#include <stdio.h>
#include <vector>
#include <bitset>
using namespace std;
FILE *f,*g;
int n,m;
bitset <100100> viz;
vector <int> v[100100];
void citire  () {
f=fopen("dfs.in","r");
g=fopen("dfs.out","w");
fscanf(f,"%d%d",&n,&m);
int x,y;
 for (int i=1;i<=m;i++) {
fscanf(f,"%d%d",&x,&y);
v[x].push_back(y);
v[y].push_back(x);

 }
}
void dfs(int x)
{
viz[x]=1;
int i;
for (i=0;i<v[x].size();i++)
        if (!viz[v[x][i]]) dfs(v[x][i]);

}


int main() {
citire();
int i,cnt=0;
for (i=1;i<=n;i++) if (!viz[i]) {
                                cnt++;
                                dfs(i);
                                }
fprintf(g,"%d",cnt);
fclose(g);
return 0;

}