For problem statement at 1000-1999/1800-1899/1800-1809/1808/problemB.txt this is a correct solution, but verifier at 1000-1999/1800-1899/1800-1809/1808/verifierB.go ends with All tests passed can you fix the verifier? package main

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

func readInt(in *bufio.Reader) int {
	n := 0
	c, err := in.ReadByte()
	for err == nil && c <= 32 {
		c, err = in.ReadByte()
	}
	for err == nil && c > 32 {
		n = n*10 + int(c-'0')
		c, err = in.ReadByte()
	}
	return n
}

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

	t := readInt(in)
	for tc := 0; tc < t; tc++ {
		n := readInt(in)
		m := readInt(in)
		cols := make([][]int64, m)
		for j := 0; j < m; j++ {
			cols[j] = make([]int64, n)
		}
		for i := 0; i < n; i++ {
			for j := 0; j < m; j++ {
				cols[j][i] = int64(readInt(in))
			}
		}
		var ans int64
		for j := 0; j < m; j++ {
			sort.Slice(cols[j], func(x, y int) bool {
				return cols[j][x] < cols[j][y]
			})
			for i := 0; i < n; i++ {
				ans += cols[j][i] * int64(2*i-n+1)
			}
		}
		fmt.Fprintln(out, ans)
	}
}