#include #define pt printf(">>>") #define mid (((l)+(r))/2) using namespace std; typedef long long ll; typedef long double ld; const ll N=1e6+10,inf=1e18+10,mod=1e9+7; ll n,k; char s[20][20]; int main(){ cin >> n >> k; for(ll i=0;i> (s[i]); for(ll i=0;i