#include <fstream>
#include <vector>

typedef struct v
{
    int begin;
    int end;
    int weight;
};

int main()
{
    std::ifstream fin;
    std::ofstream fout;
    fin.open("input.txt", std::ios::in);
    fout.open("output.txt", std::ios::out);
    int n, m;
    fin >> n >> m;
    std::vector<v> arr(m);
    for (int i = 0; i < m; ++i)
    {
        fin >> arr[i].begin >> arr[i].end >> arr[i].weight;
    }

    for (int i = 0; i < m - 1; ++i)
        for (int j = i + 1; j < m; ++j)
            if (arr[i].begin == arr[j].begin && arr[i].end == arr[j].end ||
            arr[i].begin == arr[j].end && arr[i].end == arr[j].end)
            {
                int max_weight = std::max(arr[i].weight, arr[j].weight);
                arr[i].weight = max_weight;
                arr[j].weight = max_weight;
            }
    int max = 0;
    for (int i = 0; i < m; ++i)
        if (arr[i].weight > max)
            max = arr[i].weight;
    fout << max;
    return 0;
}