#include <fstream.h> 
#include <iostream.h> 
#include <stdio.h> 
using namespace std; 
long i,comp_conex=0; 
long n,m,vizitat[100005]; 
typedef struct nod 
{ 
int info; 
nod *urm; 
} *pNod; 
pNod v[100005]; 
void citire() 
{int i,j,k,x,y; 
ifstream f("dfs.in"); 
f>>n>>m; 
pNod nou; 
for (i = 1; i <= m; i++) 

{ 

f>>x>>y; 

nou=new nod; 



nou->info=x; 



nou->urm=v[y]; 



v[y]=nou; 

nou=new nod; 

nou->info=y; 

nou->urm=v[x]; 

v[x]=nou; 

} 

f.close(); 

} 

 

void df(int nod) 

{pNod nou; 

vizitat[nod] = 1; 




for (nou=v[nod];nou!=NULL;nou=nou->urm) if(!vizitat[nou->info]) df(nou->info); 

} 

void afisare() 



{ofstream g("dfs.out"); 



g<<comp_conex; 

g.close(); 

} 

 

int main() 

{int j,k,indice=1; 

citire(); 

 



while(indice!=0) 

{indice=0; 

for(k=1;k<=n;k++) 

if(vizitat[k]==0) 

{indice=1;comp_conex++;df(k);} 

} 



afisare(); 

return 0; 




}