#include <bits/stdc++.h>

using namespace std;

const int Nmax = 1e5 + 10;
const int inf = 0x3f3f3f3f;

int n , m , i , S , crt , ans;
int nr[Nmax] , bst[Nmax];

bool marked[Nmax] , cycle , ap[Nmax] , used[Nmax];

vector < pair < int , int > > g[Nmax];
vector < int > p[Nmax] , t;
queue < int > q;

void Bford()
{
    memset(bst , inf , sizeof(bst));
    for (q.push(S),marked[S]=1,bst[S]=0; !q.empty(); q.pop())
    {
        int node = q.front(); marked[node] = 0;

        for (auto &it : g[node])
        {
            int newN , crtCost; tie(newN , crtCost) = it;
            if (bst[newN] > bst[node] + crtCost)
            {
                if (nr[newN] == n-1)
                {
                    t.push_back(newN);
                    return;
                }
                nr[newN]++;
                bst[newN] = bst[node] + crtCost;
                if (!ap[newN]) ap[newN] = 1, crt++;
                if (!marked[newN]) marked[newN] = 1, q.push(newN);
            }
        }
    }
}

void dfs(int node)
{
    used[node] = 1; ans++;

    for (auto &it : p[node])
        if (!used[it])
            dfs(it);
}

int main()
{
    #ifndef ONLINE_JUDGE
    freopen("input.in","r",stdin);
    freopen("output.out","w",stdout);
    #endif // ONLINE_JUDGE

    scanf("%d %d", &n, &m); S = 1;
    for (i = 1 ; i <= m; ++i)
    {
        int node1, node2, cost;
        scanf("%d %d %d", &node1, &node2, &cost);

        g[node1].push_back({node2 , cost});
        p[node2].push_back(node1);
    }

    for (i = 1; i <= n; ++i)
    {
        if (ap[i]) continue;
        S = i; crt = 0; cycle = 0;
        Bford();
        //if (cycle) ans += crt;
    }

    for (auto &it : t)
        if (!used[it]) dfs(it);

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

    return 0;
}