Check if n is even then every set will contain 2 adjacent elements up - to n
if ( n % 2 == 0 ) { for ( int i = 0 ; i < n / 2 ; i ++ ) { firstadj = 2 * i + 1 ; secadj = 2 * i + 2 ; cout << " ( " << firstadj << " , ▁ " << secadj << " ) STRNEWLINE " ; } } else {