#include <bits/stdc++.h>
#define al long long
#define pb push_back
#define f first
#define s second
#define ap cout
#define ak "\n"
#define all(x) x.begin(),x.end()
#define ok cout << __LINE__ << "| "<< "----------OK--------- -----" << endl;
#define deb(x) cout << __LINE__ << "| "<< #x << " = " << x<< endl;
#define fast ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
#define af(x) ap<<x;
#define ai(x) af((x ? out[1] : out[0]))
#define cin(n,b) for(al i=1;i<=n;i++)cin>>b[i];
using namespace std;
const al nn=2e6+9;
const string out[2]={"NO","YES"};
al n,d,res,ind;
string s[nn];
set<string>a[20];
set<string>cur;
void tp(){
cin>>n>>d;
for(al i=1;i<=n;i++){
string p;
cin>>p;
cur.insert(p);
}
for(auto j:cur){
s[++ind]=j;
}
if(ind==1){
af(0);
return;
}
if(d==1){
for(al i=1;i<=ind;i++){
for(al j=1;j<=4;j++){
string t;
for(al k=1;k<=4;k++){
if(j==k)continue;
t+=s[i][k];
}
a[j].insert(t);
}
}
for(al i=1;i<=n;i++){
res+=4-a[i].size();
}
af(res);
}
}
signed main(){
fast;
al tt=1;
//cin>>tt;
while(tt--){
tp();
ap<<ak;
}
}
