/* 3047 */

 #include <iostream>

 #include <string>

 #include <map>

 #include <queue>

 #include <set>

 #include <stack>

 #include <vector>

 #include <deque>

 #include <algorithm>

 #include <cstdio>

 #include <cmath>

 #include <ctime>

 #include <cstring>

 #include <climits>

 #include <cctype>

 #include <cassert>

 #include <functional>

 #include <iterator>

 #include <iomanip>

 using namespace std;

 //#pragma comment(linker,"/STACK:102400000,1024000")

 #define sti                set<int>

 #define stpii            set<pair<int, int> >

 #define mpii            map<int,int>

 #define vi                vector<int>

 #define pii                pair<int,int>

 #define vpii            vector<pair<int,int> >

 #define rep(i, a, n)     for (int i=a;i<n;++i)

 #define per(i, a, n)     for (int i=n-1;i>=a;--i)

 #define clr                clear

 #define pb                 push_back

 #define mp                 make_pair

 #define fir                first

 #define sec                second

 #define all(x)             (x).begin(),(x).end()

 #define SZ(x)             ((int)(x).size())

 #define lson            l, mid, rt<<1

 #define rson            mid+1, r, rt<<1|1

 const int maxn = 5e4+;

 int fa[maxn], dis[maxn];

 int find(int x) {

     if (fa[x] == x)

         return x;

     int tmp = fa[x];

     fa[x] = find(fa[x]);

     dis[x] += dis[tmp];

     return fa[x];

 }

 bool merge(int u, int v, int w) {

     int fu = find(u);

     int fv = find(v);

     if (fu == fv) {

         if (dis[u]+w!=dis[v])

             return false;

         return true;

     }

     fa[fv] = fu;

     dis[fv] = dis[u] + w - dis[v];

     return true;

 }

 int main() {

     ios::sync_with_stdio(false);

     #ifndef ONLINE_JUDGE

         freopen("data.in", "r", stdin);

         freopen("data.out", "w", stdout);

     #endif

     int n, m;

     int u, v, w;

     int ans;

     while (scanf("%d %d", &n, &m) != EOF) {

         rep(i, , n+) {

             fa[i] = i;

             dis[i] = ;

         }

         ans = ;

         while (m--) {

             scanf("%d %d %d", &u, &v, &w);

             if (!merge(u, v, w))

                 ++ans;

         }

         printf("%d\n", ans);

     }

     #ifndef ONLINE_JUDGE

         printf("time = %d.\n", (int)clock());

     #endif

     return ;

 }