For problem statement at 0-999/900-999/960-969/961/problemC.txt this is a correct solution, but verifier at 0-999/900-999/960-969/961/verifierC.go ends with All tests passed can you fix the verifier? ```go
package main

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

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

	// Read n
	if !scanner.Scan() {
		return
	}
	n, _ := strconv.Atoi(scanner.Text())

	// cost0[k] stores the cost to transform the k-th piece (0-indexed)
	// into a "Type 0" pattern.
	// Type 0 pattern means the top-left cell (0,0) of the piece is 0 (white).
	// Since it's a chessboard, cell (i, j) should be (i+j)%2.
	cost0 := make([]int, 4)

	for k := 0; k < 4; k++ {
		currentCost := 0
		for i := 0; i < n; i++ {
			if !scanner.Scan() {
				break
			}
			row := scanner.Text()
			for j := 0; j < n; j++ {
				// Determine if the current square needs to be changed for Type 0
				// Expected color for Type 0 at (i, j) is '0' if (i+j) is even, '1' if odd.
				var expected byte
				if (i+j)%2 == 0 {
					expected = '0'
				} else {
					expected = '1'
				}

				if row[j] != expected {
					currentCost++
				}
			}
		}
		cost0[k] = currentCost
	}

	// For a 2n x 2n chessboard with n odd:
	// If the top-left quadrant is Type 0:
	//   TL (0..n-1, 0..n-1) -> Type 0
	//   TR (0..n-1, n..2n-1) -> Starts at (0, n). Since n is odd, (0+n) is odd.
	//      Relative (0,0) corresponds to odd parity. Must be Type 1.
	//   BL (n..2n-1, 0..n-1) -> Starts at (n, 0). Odd parity. Must be Type 1.
	//   BR (n..2n-1, n..2n-1) -> Starts at (n, n). Even parity. Must be Type 0.
	// So we need 2 pieces of Type 0 and 2 pieces of Type 1.
	//
	// If the top-left quadrant is Type 1:
	//   TL -> Type 1
	//   TR -> Type 0
	//   BL -> Type 0
	//   BR -> Type 1
	// So we need 2 pieces of Type 1 and 2 pieces of Type 0.
	//
	// In both cases, the requirement is to partition the 4 pieces such that
	// 2 are converted to Type 0 and 2 are converted to Type 1.
	// The cost to convert to Type 1 is (n*n - cost0[k]).

	totalSquares := n * n
	minCost := -1

	// Iterate over all pairs of pieces to be Type 0 (indices 0..3)
	// There are C(4, 2) = 6 pairs.
	pairs := [][2]int{
		{0, 1}, {0, 2}, {0, 3},
		{1, 2}, {1, 3}, {2, 3},
	}

	for _, p := range pairs {
		currentCost := 0
		
		// Create a mask or map for quick lookup of Type 0 assignment
		isType0 := 0
		isType0 |= (1 << p[0])
		isType0 |= (1 << p[1])

		for k := 0; k < 4; k++ {
			if (isType0>>k)&1 == 1 {
				// k assigned to Type 0
				currentCost += cost0[k]
			} else {
				// k assigned to Type 1
				currentCost += (totalSquares - cost0[k])
			}
		}

		if minCost == -1 || currentCost < minCost {
			minCost = currentCost
		}
	}

	fmt.Println(minCost)
}
```