For problem statement at 1000-1999/1800-1899/1820-1829/1825/problemB.txt this is a correct solution, but verifier at 1000-1999/1800-1899/1820-1829/1825/verifierB.go ends with All 100 tests passed can you fix the verifier? ```go
package main

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

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

	var t int
	fmt.Fscan(in, &t)

	for i := 0; i < t; i++ {
		var n, m int
		fmt.Fscan(in, &n, &m)
		size := n * m
		b := make([]int, size)
		for j := 0; j < size; j++ {
			fmt.Fscan(in, &b[j])
		}

		sort.Ints(b)

		min1 := b[0]
		min2 := b[1]
		max1 := b[size-1]
		max2 := b[size-2]

		// There are two strategies:
		// 1. Place the largest element (max1) at (1,1). 
		//    We want to minimize the minimums in the subtables.
		//    We place min1 at a neighbor of (1,1) covering the larger area,
		//    and min2 at the other neighbor covering the smaller area.
		// 2. Place the smallest element (min1) at (1,1).
		//    We want to maximize the maximums in the subtables.
		//    We place max1 at a neighbor covering the larger area,
		//    and max2 at the other neighbor covering the smaller area.

		// Calculate 4 candidates:
		
		// Candidate 1: Pivot Max1 at (1,1). Min1 on side 'm', Min2 on side 'n'.
		// Subtables covering (1,2) (and thus min1) are n*(m-1). Value: max1 - min1.
		// Remaining subtables in first column (excluding 1,1) cover (2,1) (min2). Count: n-1. Value: max1 - min2.
		cand1 := int64(n*(m-1))*int64(max1-min1) + int64(n-1)*int64(max1-min2)

		// Candidate 2: Pivot Max1 at (1,1). Min1 on side 'n', Min2 on side 'm'.
		// Subtables covering (2,1) (min1) are m*(n-1). Value: max1 - min1.
		// Remaining subtables in first row cover (1,2) (min2). Count: m-1. Value: max1 - min2.
		cand2 := int64(m*(n-1))*int64(max1-min1) + int64(m-1)*int64(max1-min2)

		// Candidate 3: Pivot Min1 at (1,1). Max1 on side 'm', Max2 on side 'n'.
		cand3 := int64(n*(m-1))*int64(max1-min1) + int64(n-1)*int64(max2-min1)

		// Candidate 4: Pivot Min1 at (1,1). Max1 on side 'n', Max2 on side 'm'.
		cand4 := int64(m*(n-1))*int64(max1-min1) + int64(m-1)*int64(max2-min1)

		ans := cand1
		if cand2 > ans {
			ans = cand2
		}
		if cand3 > ans {
			ans = cand3
		}
		if cand4 > ans {
			ans = cand4
		}

		fmt.Fprintln(out, ans)
	}
}
```