For problem statement at 1000-1999/1400-1499/1420-1429/1423/problemM.txt this is a correct solution, but verifier at 1000-1999/1400-1499/1420-1429/1423/verifierM.go ends with case 1 mismatch: expected 5 got ? 1 1
! 5
exit status 1 can you fix the verifier? ```go
package main

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

var (
	reader *bufio.Reader
	writer *bufio.Writer
	minVal int
)

func query(r, c int) int {
	fmt.Fprintf(writer, "? %d %d\n", r+1, c+1)
	writer.Flush()
	var h int
	fmt.Fscan(reader, &h)
	if h < minVal {
		minVal = h
	}
	return h
}

func smawk(rows, cols []int) []int {
	if len(rows) == 0 {
		return []int{}
	}

	// Reduce columns
	stack := make([]int, 0, len(rows))
	for _, c := range cols {
		for len(stack) > 0 {
			rowIdx := len(stack) - 1
			r := rows[rowIdx]
			cTop := stack[len(stack)-1]
			vTop := query(r, cTop)
			vCur := query(r, c)
			if vCur < vTop {
				stack = stack[:len(stack)-1]
			} else {
				break
			}
		}
		if len(stack) < len(rows) {
			stack = append(stack, c)
		}
	}
	reduceCols := stack

	// Solve for odd rows recursively
	oddRows := make([]int, 0, len(rows)/2)
	for i := 1; i < len(rows); i += 2 {
		oddRows = append(oddRows, rows[i])
	}

	var oddResults []int
	if len(oddRows) > 0 {
		oddResults = smawk(oddRows, reduceCols)
	}

	result := make([]int, len(rows))
	for i, val := range oddResults {
		result[2*i+1] = val
	}

	// Fill even rows
	j := 0
	for i := 0; i < len(rows); i += 2 {
		var limit int
		if i+1 < len(rows) {
			limit = result[i+1]
		} else {
			limit = reduceCols[len(reduceCols)-1]
		}

		bestVal := int(^uint(0) >> 1)
		bestCol := -1

		k := j
		for k < len(reduceCols) {
			col := reduceCols[k]
			val := query(rows[i], col)
			if val < bestVal {
				bestVal = val
				bestCol = col
			}
			if col == limit {
				break
			}
			k++
		}
		result[i] = bestCol
		j = k
	}

	return result
}

func main() {
	reader = bufio.NewReader(os.Stdin)
	writer = bufio.NewWriter(os.Stdout)

	var n, m int
	fmt.Fscan(reader, &n, &m)

	rows := make([]int, n)
	for i := 0; i < n; i++ {
		rows[i] = i
	}
	cols := make([]int, m)
	for i := 0; i < m; i++ {
		cols[i] = i
	}

	minVal = int(^uint(0) >> 1)

	smawk(rows, cols)

	fmt.Fprintf(writer, "! %d\n", minVal)
	writer.Flush()
}
```