#include <bits/stdc++.h>
#define int long long
using namespace std;
const int MAXN = 1e5;
const int MOD = 666013;
bitset<MAXN + 1> has[6][27];
string s1[MAXN + 1];
signed main() {
int n, m, i, j;
long long ans = 0;
string s;
cin >> n >> m;
for (i = 1; i <= n; i++) {
cin >> s1[i];
for (j = 0; j < m; j++) {
if (s1[i][j] != '?')
s1[i][j] -= 'a';
else
s1[i][j] = 26;
has[j][(int)s1[i][j]][i] = 1;
}
}
bitset<MAXN + 1> aux, correct;
aux.set();
//correct.set();
for (i = 1; i <= n; i++) {
bool ok = 1;
correct = aux;
s = s1[i];
for (j = 0; j < m; j++) {
if (s[j] != 26) {
correct &= (has[j][(int)s[j]]|has[j][26]);
ok = 0;
}
}
if (ok == 1)
ans += n;
else
ans += correct.count();
//aux = correct;
}
ans -= n;
ans /= 2;
cout << ans << '\n';
return 0;
}
