#include <iostream>
#include <vector>
#include <string>
#include <unordered_map>
#include <cstdint>
using std::cout, std::cin, std::vector, std::string;
struct Hash
{
size_t operator()(const std::vector<uint8_t>& vec) const
{
std::hash<uint8_t> hasher;
size_t seed = 0;
for (int i : vec)
{
seed ^= hasher(i) + 0x0959f0d8 + (seed << 6) + (seed >> 2);
}
return seed;
}
};
vector<uint8_t> Convert(const string& str)
{
vector<uint8_t> line (str.length(), 0);
uint8_t max = 0;
for (unsigned i = 0; i < str.length(); i++)
{
bool found = false;
for (unsigned j = 0; j < i; j++)
{
if (str[j] == str[i])
{
line[i] = line[j];
found = true;
if (max < line[i]) max = line[i];
break;
}
}
if (!found) line[i] = max++;
}
return line;
}
int main()
{
int n;
cin >> n;
std::unordered_map <vector<uint8_t>, int, Hash> lines;
for (int i = 0; i < n; i++)
{
string input;
cin >> input;
lines[Convert(input)]++;
}
int num = 0;
for (auto it=lines.begin(); it!=lines.end(); it++)
{
int count = it->second;
num += (count * (count - 1)) / 2;
}
cout << num << "\n";
}
