#include <iostream>
#include <fstream>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int mtA[1001][1001], v[1001];
int N;
void dfs (int i) {
    v[i] = 1;
    for(int j = 1; j <= N; j++) {
        if(mtA[i][j] == 1 && v[j] == 0)
            dfs(j);
    }
}
int main()
{
    int M, nrComp = 0;
    f >> N >> M;
    while (M--) {
        int x, y;
        f >> x >> y;
        if(x != y) {
            mtA[x][y] = 1;
            mtA[y][x] = 1;
        }
    }
    for(int i = 1; i <= N; i++) {
        if(v[i] == 0) {
            nrComp++;
            dfs(i);
        }
    }
    g << nrComp;
    return 0;
}