#include <bits/stdc++.h>

using namespace std;

vector<string> split_string(string);

// Complete the arrayManipulation function below.
long arrayManipulation(int n, vector<vector<int>> queries) 
{
    vector <long long int> values(n);
    long long int maximum;
    for(int l=0;l<values.size();l++)
    {
        values[l]=0;
    }
    int i=0,j=0;
    for(i=0;i < queries.size(); i++)
    {
        for(j=1;j<=n;j++)
        {
            if(j==queries[i][0] || j==queries[i][1])
                values[j-1]=values[j-1]+queries[i][2];
        }
    }
    maximum=values[0];
    for(int p=1;p<values.size();p++)
    {
        if(values[p] > maximum)
            maximum=values[p];
    }
    return maximum;
    

}

int main()
{
    ofstream fout(getenv("OUTPUT_PATH"));

    string nm_temp;
    getline(cin, nm_temp);

    vector<string> nm = split_string(nm_temp);

    int n = stoi(nm[0]);

    int m = stoi(nm[1]);

    vector<vector<int>> queries(m);
    for (int i = 0; i < m; i++) {
        queries[i].resize(3);

        for (int j = 0; j < 3; j++) {
            cin >> queries[i][j];
        }

        cin.ignore(numeric_limits<streamsize>::max(), '\n');
    }

    long result = arrayManipulation(n, queries);

    fout << result << "\n";

    fout.close();

    return 0;
}

vector<string> split_string(string input_string) {
    string::iterator new_end = unique(input_string.begin(), input_string.end(), [] (const char &x, const char &y) {
        return x == y and x == ' ';
    });

    input_string.erase(new_end, input_string.end());

    while (input_string[input_string.length() - 1] == ' ') {
        input_string.pop_back();
    }

    vector<string> splits;
    char delimiter = ' ';

    size_t i = 0;
    size_t pos = input_string.find(delimiter);

    while (pos != string::npos) {
        splits.push_back(input_string.substr(i, pos - i));

        i = pos + 1;
        pos = input_string.find(delimiter, i);
    }

    splits.push_back(input_string.substr(i, min(pos, input_string.length()) - i + 1));

    return splits;
}