For problem statement at 1000-1999/1800-1899/1810-1819/1818/problemB.txt this is a correct solution, but verifier at 1000-1999/1800-1899/1810-1819/1818/verifierB.go ends with test 5 failed
input:
1
78
expected: 2 1 4 3 6 5 8 7 10 9 12 11 14 13 16 15 18 17 20 19 22 21 24 23 26 25 28 27 30 29 32 31 34 33 36 35 38 37 40 39 42 41 44 43 46 45 48 47 50 49 52 51 54 53 56 55 58 57 60 59 62 61 64 63 66 65 68 67 70 69 72 71 74 73 76 75 78 77
got: 77 78 75 76 73 74 71 72 69 70 67 68 65 66 63 64 61 62 59 60 57 58 55 56 53 54 51 52 49 50 47 48 45 46 43 44 41 42 39 40 37 38 35 36 33 34 31 32 29 30 27 28 25 26 23 24 21 22 19 20 17 18 15 16 13 14 11 12 9 10 7 8 5 6 3 4 1 2

exit status 1 can you fix the verifier? package main

import (
	"bufio"
	"fmt"
	"os"
)

func main() {
	reader := bufio.NewReader(os.Stdin)
	writer := bufio.NewWriter(os.Stdout)
	defer writer.Flush()

	var t int
	if _, err := fmt.Fscan(reader, &t); err != nil {
		return
	}

	for tc := 0; tc < t; tc++ {
		var n int
		fmt.Fscan(reader, &n)

		if n == 1 {
			fmt.Fprintln(writer, 1)
		} else if n%2 != 0 {
			fmt.Fprintln(writer, -1)
		} else {
			for i := n; i >= 1; i -= 2 {
				if i < n {
					fmt.Fprint(writer, " ")
				}
				fmt.Fprintf(writer, "%d %d", i-1, i)
			}
			fmt.Fprintln(writer)
		}
	}
}