For problem statement at 2000-2999/2000-2099/2090-2099/2097/problemB.txt this is a correct solution, but verifier at 2000-2999/2000-2099/2090-2099/2097/verifierB.go ends with All 120 tests passed. can you fix the verifier? ```go
package main

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

const MOD = 1000000007

var sc *bufio.Scanner

func init() {
	sc = bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)
	sc.Buffer(make([]byte, 0, 1024*1024), 1024*1024)
}

func readInt() int {
	sc.Scan()
	x, _ := strconv.Atoi(sc.Text())
	return x
}

func abs(x int) int {
	if x < 0 {
		return -x
	}
	return x
}

func solve() int {
	n := readInt()
	m := readInt()
	k := readInt()
	total := n * m

	oddX := make([]int, k+1)
	oddY := make([]int, k+1)
	isOdd := make([]bool, total)

	for i := 0; i <= k; i++ {
		x := readInt()
		y := readInt()
		oddX[i] = x
		oddY[i] = y
		id := (x-1)*m + (y-1)
		isOdd[id] = true
	}

	setSize := make([]int, k)
	setElem := make([][2]int, k)
	cellSets := make([][]int, total)

	for i := 0; i < k; i++ {
		x1, y1 := oddX[i], oddY[i]
		x2, y2 := oddX[i+1], oddY[i+1]
		dist := abs(x1-x2) + abs(y1-y2)
		if dist != 2 {
			return 0
		}
		var cand [][2]int
		if x1 == x2 {
			cand = append(cand, [2]int{x1, (y1 + y2) / 2})
		} else if y1 == y2 {
			cand = append(cand, [2]int{(x1 + x2) / 2, y1})
		} else {
			cand = append(cand, [2]int{x1, y2}, [2]int{x2, y1})
		}
		var valid []int
		for _, c := range cand {
			cx, cy := c[0], c[1]
			if cx >= 1 && cx <= n && cy >= 1 && cy <= m {
				id := (cx-1)*m + (cy-1)
				if !isOdd[id] {
					valid = append(valid, id)
				}
			}
		}
		if len(valid) == 0 {
			return 0
		}
		setSize[i] = len(valid)
		setElem[i][0] = valid[0]
		if len(valid) == 2 {
			setElem[i][1] = valid[1]
		}
		for _, v := range valid {
			cellSets[v] = append(cellSets[v], i)
		}
	}

	assigned := make([]bool, total)
	queue := make([]int, 0, k)
	for i := 0; i < k; i++ {
		if setSize[i] == 1 {
			queue = append(queue, i)
		}
	}

	for len(queue) > 0 {
		i := queue[0]
		queue = queue[1:]
		if setSize[i] == -1 {
			continue
		}
		if setSize[i] != 1 {
			continue
		}
		c := setElem[i][0]
		if assigned[c] {
			return 0
		}
		assigned[c] = true
		setSize[i] = -1
		for _, j := range cellSets[c] {
			if setSize[j] <= 0 {
				continue
			}
			if setElem[j][0] == c {
				if setSize[j] == 2 {
					setElem[j][0] = setElem[j][1]
					setSize[j] = 1
					queue = append(queue, j)
				} else {
					return 0
				}
			} else if setSize[j] == 2 && setElem[j][1] == c {
				setSize[j] = 1
				queue = append(queue, j)
			}
		}
	}

	visited := make([]bool, total)
	ways := 1

	for i := 0; i < k; i++ {
		if setSize[i] != 2 {
			continue
		}
		u := setElem[i][0]
		if !visited[u] {
			vCount := 0
			eCount := 0
			stack := []int{u}
			visited[u] = true
			for len(stack) > 0 {
				curr := stack[len(stack)-1]
				stack = stack[:len(stack)-1]
				vCount++
				for _, j := range cellSets[curr] {
					if setSize[j] == 2 {
						eCount++
						other := setElem[j][0]
						if other == curr {
							other = setElem[j][1]
						}
						if !visited[other] {
							visited[other] = true
							stack = append(stack, other)
						}
					}
				}
			}
			eCount /= 2
			if eCount > vCount {
				return 0
			} else if eCount == vCount {
				ways = (ways * 2) % MOD
			} else if eCount == vCount-1 {
				ways = (ways * vCount) % MOD
			} else {
				return 0
			}
		}
	}

	return ways
}

func main() {
	t := readInt()
	for i := 0; i < t; i++ {
		fmt.Println(solve())
	}
}
```