#include <string>
#include <vector>
#include <list>
#include <cmath>
#include <algorithm>
#include <map>
#include <set>
#include <iostream>
#include <cstdio>
#include <cstdlib>
using namespace std;

class FoxAndWord {
  public:
    int howManyPairs(vector <string> words);
};

int FoxAndWord::howManyPairs(vector <string> words)
{
  return 0;
}