#include <bits/stdc++.h>
#define pb push_back

using namespace std;

vector <int> la[100005];
bitset <100005> viz;

void dfs(int nod){
    viz[nod] = 1;
    for(auto it : la[nod]){
        if(!viz[it]){
            dfs(it);
        }
    }
}

int main()
{
    int n,m,i,x,y;
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    scanf("%d %d",&n,&m);
    for(i = 1;i <= m;i++){
        scanf("%d %d",&x,&y);
        la[x].pb(y);
        la[y].pb(x);
    }
    int sol = 0;
    for(i = 1;i <= n;i++){
        if(!viz[i]){
            dfs(i);
            sol++;
        }
    }
    printf("%d",sol);
    return 0;
}