winter damn freeze cold Nvodsk that s group n friend prefer taxi order pizza girl the phone number city consist pair digit example 123456 each friend phonebook size si that s number phone number we know taxi number consist identical digit example 222222 number pizza delivery necessarily decrease sequence different digit example 987321 number girl numbersyou give friend phone book Calculate friend well interested thing maximal number phone number type if phone book person contain number time count twice that number take consideration number time occur phone book