#include #include #define rep(i,b) for(int i=0;i=0;i--) #define rep1(i,b) for(int i=1;i using mpq = priority_queue, greater>; template bool chmax(T &a, const T &b) { if (a bool chmin(T &a, const T &b) { if (b ll sumv(const vector&a){ll res(0);for(auto&&x:a)res+=x;return res;} bool yn(bool a) { if(a) {cout << "Yes" << endl; return 1;} else {cout << "No" << endl; return 0;}} #define dame { cout << "No" << endl; return 0;} #define dame1 { cout << -1 << endl; return 0;} #define test(x) cout << "test" << x << endl; #define deb(x,y) cout << x << " " << y << endl; #define deb3(x,y,z) cout << x << " " << y << " " << z << endl; #define deb4(x,y,z,x2) cout << x << " " << y << " " << z << " " << x2 << endl; #define out cout << ans << endl; #define outv fore(yans , ans) cout << yans << "\n"; #define show(x) cerr<<#x<<" = "<; using pil = pair; using pli = pair; using pii = pair; using tp = tuple; using vi = vector; using vl = vector; using vs = vector; using vb = vector; using vpii = vector; using vpli = vector; using vpll = vector; using vpil = vector; using vvi = vector>; using vvl = vector>; using vvs = vector>; using vvb = vector>; using vvpii = vector>; using vvpli = vector>; using vvpll = vector; using vvpil = vector; using mint = modint998244353; using vm = vector; using vvm = vector>; vector dx={1,0,-1,0,1,1,-1,-1},dy={0,1,0,-1,1,-1,1,-1}; ll gcd(ll a, ll b) { return a?gcd(b%a,a):b;} ll lcm(ll a, ll b) { return a/gcd(a,b)*b;} const double eps = 1e-10; const ll LINF = 1001002003004005006ll; const int INF = 1001001001; int main(){ int n,m; cin>>n>>m; vs s(n); rep(i,n) cin>>s[i]; map mp; rep(i,n){ mp[s[i]].pb(i); } ll ans = 0; rep(ii,m+1){ string pre = s[0].substr(0,ii); string aft = s[0].substr(ii,m-ii); rep(j,26){ char c = 'a' + j; string t = pre + c + aft; vs prev(m+2),aftv(m+2); rep1(i,m+2){ prev[i] = prev[i-1] + t[i-1]; aftv[m+1-i] = t[m+1-i] + aftv[m+2-i]; } vb flg(n); flg[0] = true; rep(i,m+1){ string tmp = prev[i] + aftv[i+1]; vi v; if (mp.count(tmp)) v = mp[tmp]; fore(y , v) flg[y] = true; } bool ok = true; rep1(i,n) ok &= flg[i]; if (ok) ans++; } } out; return 0; }