For problem statement at 1000-1999/1200-1299/1210-1219/1216/problemC.txt this is a correct solution, but verifier at 1000-1999/1200-1299/1210-1219/1216/verifierC.go ends with All tests passed can you fix the verifier? ```go
package main

import (
	"fmt"
)

func main() {
	var x1, y1, x2, y2 int
	var x3, y3, x4, y4 int
	var x5, y5, x6, y6 int

	fmt.Scan(&x1, &y1, &x2, &y2)
	fmt.Scan(&x3, &y3, &x4, &y4)
	fmt.Scan(&x5, &y5, &x6, &y6)

	// Collect all unique x and y coordinates within the white sheet
	xs := []int{x1, x2}
	ys := []int{y1, y2}

	// Add clipped coordinates from black sheets
	if x3 > x1 && x3 < x2 {
		xs = append(xs, x3)
	}
	if x4 > x1 && x4 < x2 {
		xs = append(xs, x4)
	}
	if x5 > x1 && x5 < x2 {
		xs = append(xs, x5)
	}
	if x6 > x1 && x6 < x2 {
		xs = append(xs, x6)
	}

	if y3 > y1 && y3 < y2 {
		ys = append(ys, y3)
	}
	if y4 > y1 && y4 < y2 {
		ys = append(ys, y4)
	}
	if y5 > y1 && y5 < y2 {
		ys = append(ys, y5)
	}
	if y6 > y1 && y6 < y2 {
		ys = append(ys, y6)
	}

	// Sort xs and ys
	sortInts(xs)
	sortInts(ys)
	xs = unique(xs)
	ys = unique(ys)

	// Check each cell
	for i := 0; i < len(xs)-1; i++ {
		for j := 0; j < len(ys)-1; j++ {
			// Midpoint of cell
			mx2 := xs[i] + xs[i+1]
			my2 := ys[j] + ys[j+1]
			// mx2/2, my2/2 is the midpoint (using *2 to avoid fractions)

			// Check if midpoint is strictly inside white sheet
			// strictly inside: x1 < mx < x2, y1 < my < y2
			// Using doubled coords: 2*x1 < mx2 < 2*x2
			if mx2 <= 2*x1 || mx2 >= 2*x2 || my2 <= 2*y1 || my2 >= 2*y2 {
				continue
			}

			// Check if midpoint is strictly inside black sheet 1
			in1 := mx2 > 2*x3 && mx2 < 2*x4 && my2 > 2*y3 && my2 < 2*y4

			// Check if midpoint is strictly inside black sheet 2
			in2 := mx2 > 2*x5 && mx2 < 2*x6 && my2 > 2*y5 && my2 < 2*y6

			if !in1 && !in2 {
				fmt.Println("YES")
				return
			}
		}
	}

	fmt.Println("NO")
}

func sortInts(a []int) {
	// Simple sort
	for i := 0; i < len(a); i++ {
		for j := i + 1; j < len(a); j++ {
			if a[j] < a[i] {
				a[i], a[j] = a[j], a[i]
			}
		}
	}
}

func unique(a []int) []int {
	if len(a) == 0 {
		return a
	}
	res := []int{a[0]}
	for i := 1; i < len(a); i++ {
		if a[i] != a[i-1] {
			res = append(res, a[i])
		}
	}
	return res
}
```