#include <iostream>

 #include <cstring>

 #include <cstdlib>

 #include <cstdio>

 #include <cctype>

 #include <cmath>

 #include <algorithm>

 #include <numeric>

 #include <string>

 #pragma comment(linker, "/STACK:102400000,102400000")

 using namespace std;

 int cnt = ;

 const int V = ;

 int father[V];

 int getFather (int x) {

     if (father[x] != x) {

         father[x] = getFather (father[x]);

     }

     return father[x];

 }

 void Union (int p, int q) {

     int x = getFather (p);

     int y = getFather (q);

     if (x != y) {

         father[y] = x;

         cnt ++;

     }

 }

 int main () {

     int n, road_n;

     while (~scanf("%d", &n)) {

         if (!n) break;

         scanf("%d", &road_n);//cin >> road_n;

         cnt = ;

         for (int i = ; i <= n; ++ i) {

             father[i] = i;

         }

         for (int i =  ; i < road_n; ++ i) {

             int x, y; //cin >> x >> y;

             scanf("%d%d", &x, &y);

             Union (x, y);

         }

         //cout << "cnt :   " << cnt << endl;

         cout << n -  - cnt << endl;

     }

     return ;

 }