#include <bits/stdc++.h>
#define int long long
using namespace std;
const int MAXN = 1e5;
const int MOD = 666013;
map< int , int >f[( 1 << 6 )];
string s1[MAXN + 1];
signed main() {
int n , m , i , mask , j , x , p , ok;
string s;
cin >> n >> m;
long long ans = 0;
for( j = 1 ; j <= n ; j++ ) {
cin >> s1[j];
}
sort(s1 + 1, s1+n+1, [&]( string a , string b ){
int cnt = 0 , cnt1 = 0 , i;
for( i = 0 ; i < m ; i++ ) {
cnt += a[i] != '?';
cnt1 += b[i] != '?';
}
return cnt < cnt1;
});
for( j= 1 ; j <= n ; j++ ) {
string s = s1[j];
x = 0;
for( mask = 1 ; mask < ( 1 << m ) ; mask++ ) {
x =0 , p = 1 , ok = 1;
for( i = 0 ; i < m ; i++ ) {
if( mask & ( 1 << i ) ) {
if( s[i] == '?' )
ok = 0;
x += p * ( s[i] - 'a' );
}
p *= 26;
}
if( ok == 1 ) {
if( !f[mask].empty() ) {
ans += f[mask].size();
if( f[mask].find( x ) != f[mask].end() )
ans += f[mask][x];
}
//ans += fr[mask].size() - fr[mask][x];
}
}
mask = 0;
x = 0 , p = 1;
for( i = 0 ; i < m ; i++ ) {
if( s[i] != '?' ) {
mask |= ( 1 << i );
x += p * ( s[i] - 'a' );
}
p *= 26;
}
f[mask][x]++;
}
cout << ans << '\n';
return 0;
}
