Why is my code not opening the text file $??$ I keep getting an error message $??$ Am I inserting the text file into the program incorrectly $?$

#include

#include

using namespace std;

$//$ Function to calculate piece value

int getPieceValue$($char piece$)\{$

switch $($piece$)\{$

case $\text{'}$P$\text{'}$: case $\text{'}$p$\text{'}$: return $1$;

case $\text{'}$N$\text{'}$: case $\text{'}$n$\text{'}$: return $3$;

case $\text{'}$B$\text{'}$: case $\text{'}$b$\text{'}$: return $3$;

case $\text{'}$R$\text{'}$: case $\text{'}$r$\text{'}$: return $5$;

case $\text{'}$Q$\text{'}$: case $\text{'}$q$\text{'}$: return $9$;

default: return $0$; $//$ For kings and empty spaces

$\}$

$\}$

$//$ Function to check if piece is black

bool isBlackPiece$($char piece$)\{$

return piece $>=\text{'}$A$\text{'}$ && piece Z$\text{'}$;

$\}$

$//$ Function to read and display chessboard, and calculate scores

void processChessboard$($ifstream& file$)\{$

char board$[8][8]$;

int blackScore $=0,$ whiteScore $=0$;

$//$ Reading chessboard $(8$x$8$ characters$)$

for $($int i $=0$; i $<mtext></mtext><mn>8</mn>$; i$++)\{$

for $($int j $=0$; j $<mtext></mtext><mn>8</mn>$; j$++)\{$

file $>>$ board$[$i$][$j$]$;

char piece $=$ board$[$i$][$j$]$;

if $($piece $!=\text{'}.\text{'})\{$

int value $=$ getPieceValue$($piece$)$;

if $($isBlackPiece$($piece$))\{$

blackScore $+=$ value;

$\}$

else $\{$

whiteScore $+=$ value;

$\}$

$\}$

$\}$

$\}$

$//$ Display the chessboard

cout $$ "Chessboard:" $$ endl;

for $($int i $=0$; i $<mtext></mtext><mn>8</mn>$; i$++)\{$

for $($int j $=0$; j $<mtext></mtext><mn>8</mn>$; j$++)\{$

cout $$ board$[$i$][$j;

$\}$

cout $$ endl;

$\}$

$//$ Display the scores

cout $$ "Black Pieces Value: $"$ blackScore $$ endl;

cout $$ "White Pieces Value: $"$ whiteScore $$ endl;

cout endl;

$\}$

int main$()\{$

ifstream file$("$chessboards$.$txt$")$;

if $(!$file$)\{$

cerr $$ "Error opening file!" $$ endl;

return $1$;

$\}$

$//$ Processing each chessboard in the file

while $(!$file.eof$())\{$

processChessboard$($file$)$;

$\}$

file.close$()$;

return $0$;

$\}$