#include using namespace std; typedef signed long long ll; #undef _P #define _P(...) (void)printf(__VA_ARGS__) #define FOR(x,to) for(x=0;x<(to);x++) #define FORR(x,arr) for(auto& x:arr) #define ITR(x,c) for(__typeof(c.begin()) x=c.begin();x!=c.end();x++) #define ALL(a) (a.begin()),(a.end()) #define ZERO(a) memset(a,0,sizeof(a)) #define MINUS(a) memset(a,0xff,sizeof(a)) //------------------------------------------------------- int N; string S[2002]; ll mo=1000000007; int cost[2020][2020]; ll ret[2020]; ll dp[2020]; const int CN=4001; ll C[CN][CN]; ll fact[CN]; void solve() { int i,j,k,l,r,x,y; string s; fact[0]=1; FOR(i,2020) fact[i+1]=fact[i]*(i+1)%mo; FOR(i,CN) for(j=0;j<=i;j++) C[i][j]=(j==0||j==i)?1:(C[i-1][j-1]+C[i-1][j])%mo; cin>>N; FOR(i,N) cin>>S[i]; sort(S,S+N); FOR(y,N) { cost[y][y]=cost[y][N]=cost[N][y]=1; FOR(x,y) { cost[x][y]=1; while(cost[x][y]<=S[x].size() && cost[x][y]<=S[y].size() && S[x][cost[x][y]-1]==S[y][cost[x][y]-1]) cost[x][y]++; cost[y][x]=cost[x][y]; } } FOR(y,N) for(x=y+1;x<=N;x++) (ret[x]+=cost[y][y+1]*C[N-(y+1)][x-(y+1)]%mo*fact[x])%=mo; FOR(x,N) for(y=x+1;y