#include <bits/stdc++.h>
using namespace std;
#define int long long
#define all(a) (a).begin(),(a).end()
#define rep(i, n) for(int i = 0; i < (n); i++)
#define pb push_back
#define rep1(i, n) for(int i = 1; i <= (n); i++)
const int mod = 1e9 + 7;
signed main() {
int n, m;
cin >> n >> m;
map<string, int> mp;
for (int j = 0; j < m; j++) {
string s;
cin >> s;
mp[s]++;
}
int ans = 0;
for (int i = 1; i < n; i++) {
for (int j = 0; j < m; j++) {
string s;
cin >> s;
string s1 = "";
string s2 = "";
for (int i = 0; i < s.size() - 1; i++) {
s1 += s[i];
}
for (int i = 1; i < s.size(); i++) {
s2 += s[i];
}
if(mp[s1] > 0){
mp[s] += mp[s1];
}
if(mp[s2] > 0){
mp[s] += mp[s2];
}
if(i == n - 1){
ans += mp[s];
}
}
}
cout << ans << endl;
return 0;
}
