#include <iostream>
#include <bitset>
#include <vector>
#include <algorithm>
#include <cassert>
using ll = long long;
#define debug(x) #x << " = " << x << '\n'
const int MAXN = 5e4;
const int MAXM = 6;
const int SIGMA = 26;
std::bitset<MAXN> who[6][SIGMA + 1];
std::bitset<MAXN> cand;
std::bitset<MAXN> all;
int main() {
int n, m;
std::cin >> n >> m;
std::vector<std::string> s(n);
for (int i = 0; i < n; i++) {
std::cin >> s[i];
for (char &c : s[i]) {
if (c == '?') {
c = 0;
} else {
c -= 'a';
c++;
}
}
for (int j = 0; j < m; j++) {
who[j][s[i][j]][i] = true;
}
}
for (int i = 0; i < n; i++) {
all[i] = true;
}
ll answer = 0;
for (int i = 0; i < n; i++) {
cand = all;
for (int j = 0; j < m; j++) {
if (s[i][j] != 0) {
cand &= who[j][s[i][j]] | who[j][0];
}
}
// for (int j = 0; j < n; j++) {
// std::cout << cand[j];
// }
// std::cout << '\n';
answer += cand.count();
}
answer -= n;
std::cout << answer / 2;
return 0;
}
// a treia oara e cu noroc
