#include<fstream.h>
#include<stdlib.h>
#define dim 100001
int *a[dim],viz[dim];
void dfs(int vf)
{int k;
 viz[vf]=1;
 for(k=1;k<=a[vf][0];k++)
  if(!viz[a[vf][k]])
   dfs(a[vf][k]);
}
int main()
{ifstream f("dfs.in");
ofstream g("dfs.out");
unsigned long n,i,m;
int x,y;

f>>n>>m;
for(i=1;i<=n;i++)
 {a[i]=(int*)realloc(a[i],sizeof(int));
  a[i][0]=0;
 }
for(i=1;i<=m;i++)
 {f>>x>>y;
  a[x][0]++;
  a[x]=(int*)realloc(a[x],a[x][0]*sizeof(int));
  a[x][a[x][0]]=y;
  a[y][0]++;
  a[y]=(int*)realloc(a[y],a[y][0]*sizeof(int));
  a[y][a[y][0]]=x;
 }
f.close();

unsigned long cont=0;
for(i=1;i<=n;i++)
 if(!viz[i])
   {cont++;
    dfs(i);
   }

g<<cont<<'\n';
g.close();
return 0;
}