#define taskname "C"
#include <bits/stdc++.h>
#define int long long
#define ii pair<int,int>
#define ff first
#define ss second

using namespace std;
const int maxn = 1e4 + 10;
vector<ii> adj[maxn];
int pa[maxn][20], dep[maxn], dis[maxn], p[maxn], n, m;
array<int, 4> e[maxn];

inline int fp(int u) {return !p[u] ? u : p[u] = fp(p[u]);}

inline bool uni(int u, int v)
{
    if ((u = fp(u)) == (v = fp(v))) return 0;
    return p[v] = u;
}

void DFS(int u = 1, int par = 0)
{
    for (auto [v, c]: adj[u]) if (v != par)
    {
        dep[v] = dep[u] + 1;
        dis[v] = dis[u] + c;
        pa[v][0] = u;
        DFS(v, u);
    }
}

inline int lca(int u, int v)
{
    if (dep[u] > dep[v]) swap(u, v);
    int dif = dep[v] - dep[u];
    for (int i=19; i>=0; i--) if (dif >> i & 1) v = pa[v][i];
    if (v == u) return u;
    for (int i=19; i>=0; i--) if (pa[v][i] != pa[u][i]) v = pa[v][i], u = pa[u][i];
    return pa[u][0];
}

inline int cal(int u, int v) {return dis[u] + dis[v] - 2 * dis[lca(u, v)];}

inline int sol(int m, int u, int v, int add)
{
    if (dep[u] > dep[v]) swap(u, v);
    if (cal(m, u) + cal(m, v) == cal(u, v)) return 0;
    return add + cal(u, v);
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);
    cin>>n>>m;
    for (int i=1; i<=m; i++) cin>>e[i][1]>>e[i][2]>>e[i][0], e[i][3] = i;
    vector<int> ve;
    for (int i=1; i<=m; i++) if (uni(e[i][1], e[i][2]))
    {
        adj[e[i][1]].emplace_back(e[i][2], e[i][0]);
        adj[e[i][2]].emplace_back(e[i][1], e[i][0]);
    } else ve.emplace_back(i);

    DFS();
    for (int i=1; i<20; i++)
        for (int j=1; j<=n; j++)
            pa[j][i] = pa[pa[j][i-1]][i-1];

    int ans = 0;
    for (int i=0; i<ve.size()-1; i++)
        for (int j=i+1; j<ve.size(); j++)
        {
            auto [c1, u1, v1, id1] = e[ve[i]];
            auto [c2, u2, v2, id2] = e[ve[j]];
            if (u1 == u2) ans = __gcd(ans, sol(u1, v1, v2, add));
            else if (u1 == v2) ans = __gcd(ans, sol(u1, u2, v1, add));
            else if (v1 == u2) ans = __gcd(ans, sol(v1, u1, v2, add));
            else if (v1 == v2) ans = __gcd(ans, sol(v1, u1, u2, add));
        }
    for (int i: ve)
    {
        auto [c, u, v, id] = e[i];
        ans = __gcd(ans, c + cal(u, v));
    }
    cout<<ans;
}

answer.code: In function ‘int main()’:
answer.code:76:60: error: ‘add’ was not declared in this scope; did you mean ‘std::filesystem::perm_options::add’?
   76 |             if (u1 == u2) ans = __gcd(ans, sol(u1, v1, v2, add));
      |                                                            ^~~
      |                                                            std::filesystem::perm_options::add
In file included from /usr/include/c++/13/filesystem:48,
                 from /usr/include/x86_64-linux-gnu/c++/13/bits/stdc++.h:200,
                 from answer.code:2:
/usr/include/c++/13/bits/fs_fwd.h:211:7: note: ‘std::filesystem::perm_options::add’ declared here
  211 |       add       = 0x2,
      |       ^~~
answer.code:77:65: error: ‘add’ was not declared in this scope; did you mean ‘std::filesystem::perm_options::add’?
   77 |             else if (u1 == v2) ans = __gcd(ans, sol(u1, u2, v1, add));
      |                                                                 ^~~
      |                                                                 std::filesystem::perm_options::add
/usr/include/c++/13/bits/fs_fwd.h:211:7: note: ‘std::filesystem::perm_options::add’ declared here
  211 |       add       = 0x2,
      |       ^~~
answer.code:78:65: error: ‘add’ was not declared in this scope; did you mean ‘std::filesystem::perm_options::add’?
   78 |             else if (v1 == u2) ans = __gcd(ans, sol(v1, u1, v2, add));
      |                                                                 ^~~
      |                                                                 std::filesystem::perm_options::add
/usr/include/c++/13/bits/fs_fwd.h:211:7: note: ‘std::filesystem::perm_options::add’ declared here
  211 |       add       = 0x2,
      |       ^~~
answer.code:79:65: error: ‘add’ was not declared in this scope; did you mean ‘std::filesystem::perm_options::add’?
   79 |             else if (v1 == v2) ans = __gcd(ans, sol(v1, u1, u2, add));
      |                                                                 ^~~
      |                                                                 std::filesystem::perm_options::add
/usr/include/c++/13/bits/fs_fwd.h:211:7: note: ‘std::filesystem::perm_options::add’ declared here
  211 |       add       = 0x2,
      |       ^~~