Stores the array of large numbers in integer format
List < List < int > > x = new List < List < int > > ( 1000 ) ; for ( int i = 0 ; i < k ; i ++ ) x . Add ( new List < int > ( ) ) ; for ( int i = 0 ; i < k ; i ++ ) { for ( int j = 0 ; j < N ; j ++ ) {