For problem statement at 1000-1999/1400-1499/1470-1479/1472/problemF.txt this is a correct solution, but verifier at 1000-1999/1400-1499/1470-1479/1472/verifierF.go ends with Test 1 failed: expected "YES" got "NO"
Input:
1
1 7
1 1
2 6
2 7
1 4
2 8
2 9
1 4

exit status 1 can you fix the verifier? package main

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

type Cell struct {
	r, c int
}

func main() {
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Split(bufio.ScanWords)

	buf := make([]byte, 0, 64*1024)
	scanner.Buffer(buf, 1024*1024)

	var t int
	if scanner.Scan() {
		t, _ = strconv.Atoi(scanner.Text())
	}

	out := bufio.NewWriter(os.Stdout)
	defer out.Flush()

	for tc := 0; tc < t; tc++ {
		scanner.Scan()
		scanner.Scan()
		m, _ := strconv.Atoi(scanner.Text())

		cells := make([]Cell, m)
		for i := 0; i < m; i++ {
			scanner.Scan()
			cells[i].r, _ = strconv.Atoi(scanner.Text())
			scanner.Scan()
			cells[i].c, _ = strconv.Atoi(scanner.Text())
		}

		sort.Slice(cells, func(i, j int) bool {
			if cells[i].c != cells[j].c {
				return cells[i].c < cells[j].c
			}
			return cells[i].r < cells[j].r
		})

		possible := true
		has_pending := false
		prev_c := 0
		prev_r := 0

		for i := 0; i < m; {
			if i+1 < m && cells[i].c == cells[i+1].c {
				if has_pending {
					possible = false
					break
				}
				i += 2
			} else {
				c := cells[i].c
				r := cells[i].r
				if has_pending {
					diff_c := c - prev_c
					expected_mod := 0
					if r == prev_r {
						expected_mod = 1
					}
					if diff_c%2 != expected_mod {
						possible = false
						break
					}
					has_pending = false
				} else {
					has_pending = true
					prev_c = c
					prev_r = r
				}
				i += 1
			}
		}
		
		if has_pending {
			possible = false
		}

		if possible {
			fmt.Fprintln(out, "YES")
		} else {
			fmt.Fprintln(out, "NO")
		}
	}
}