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

#define BUF_SIZE 16384
char buf[BUF_SIZE];
int pbuf=BUF_SIZE;
FILE*fi;
inline char nextch(){
    if(pbuf==BUF_SIZE){
        fread(buf, BUF_SIZE, 1, fi);
        pbuf=0;
    }
    return buf[pbuf++];
}
inline int nextnum(){
    int a=0;
    char c=nextch();
    while(c<'0' || c>'9')
        c=nextch();
    while('0'<=c && c<='9'){
        a=a*10+c-'0';
        c=nextch();
    }
    return a;
}

std::vector <int> G[100001];
char vst[100001];

void dfs(int nod){
    for(int i=0;i<G[nod].size();i++)
        if(vst[G[nod][i]]==0){
            vst[G[nod][i]]=1;
            dfs(G[nod][i]);
        }
}

int main(){
    int n, m;
    FILE*fo;
    fi=fopen("dfs.in","r");
    fo=fopen("dfs.out","w");
    n=nextnum();
    m=nextnum();
    for(int i=0;i<m;i++){
        int a=nextnum(), b=nextnum();
        G[a].push_back(b);
        G[b].push_back(a);
    }
    int x=0;
    for(int i=1;i<=n;i++)
        if(vst[i]==0){
            vst[i]=1;
            x++;
            dfs(i);
        }
    fprintf(fo,"%d", x);
    fclose(fi);
    fclose(fo);
    return 0;
}