#include <bits/stdc++.h>
using namespace std;
const int NMAX = 50005;
const int CINCO = 5;
const int SEIS = 6;
const int SIETE = 7;
int n, m;
char a[NMAX][SIETE];
map<int, int> fr[1 << SEIS];
void read() {
cin >> n >> m;
for (int i = 1; i <= n; i++) {
cin >> a[i];
}
}
int make_hash(char s[], int m) {
int mask = 0;
for (int i = 0; i < m; i++) {
int val = 0;
if (s[i] != '?') val = s[i] - 'a' + 1;
mask |= val << (i * CINCO);
}
return mask;
}
inline int hash_replace(int mask, int pos, int val) {
return (mask & ~(((1 << CINCO) - 1) << (pos * CINCO))) | (val << (pos * CINCO));
}
int query(char a[]) {
int qmask = 0, cnt = 0, len = 0;
char s[SIETE] = {0};
for (int i = 0; i < m; i++) {
if (a[i] == '?') {
qmask |= 1 << i;
} else {
s[len++] = a[i];
}
}
for (int mask = 0; mask < 1 << len; mask++) {
int h = make_hash(s, len);
for (int i = 0; i < len; i++) {
if (mask & (1 << i)) {
h = hash_replace(h, i, 0);
}
}
cnt += fr[qmask][h];
}
return cnt;
}
void update(char a[]) {
for (int mask = 0; mask < 1 << m; mask++) {
char s[SEIS];
int len = 0;
for (int i = 0; i < m; i++) {
if (!((mask >> i) & 1)) {
s[len++] = a[i];
}
}
fr[mask][make_hash(s, len)]++;
}
}
int solve() {
int ans = 0;
for (int i = 1; i <= n; i++) {
ans += query(a[i]);
update(a[i]);
}
return ans;
}
signed main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
ios_base::sync_with_stdio(false);
cin.tie(0);
cout.tie(0);
read();
cout << solve() << '\n';
return 0;
}
