#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;

class Graph
{
private:
    vector<vector<pair<int, int>>> matrix;
public:
    Graph() = default;
    Graph(size_t nodes, size_t edges);
    Graph(size_t nodes, size_t edges, istream &is);
};

Graph::Graph (size_t nodes, size_t edges)
{
    matrix.resize (nodes);
    for (auto &v : matrix)
        v.resize (nodes);
}

Graph::Graph(size_t nodes, size_t edges, istream &is) : Graph(nodes, edges)
{
    
}

int main() {
    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
    return 0;
}