#include <stdio.h>
#include <vector>

using namespace std;
FILE *f=fopen("dfs.in","r");
FILE *g=fopen("dfs.out","w");
vector<int>a[100005];

int use[100005],i,n,x,y,m,nr;

void df(int k){
    int i;
    vector<int>::iterator it;
for(it=a[k].begin();it!=a[k].end();it++)
if (use[*it]==0){use[*it]=1;df(*it);}
}


int main()
{
fscanf(f,"%d%d",&n,&m);
for(i=1;i<=m;i++)
{
fscanf(f,"%d%d",&x,&y);
a[x].push_back(y);
a[y].push_back(x);
}
for(i=1;i<=n;i++)
if (use[i]==0){nr++;use[i]=1;df(i);}

fprintf(g,"%d",nr);
fclose(g);
return 0;
}