use strict;

use Data::Dump qw( dump );

my %hash = (
    inst => { 
	dept => { 
	    rollno=> { 
		name  => 100, 
		name1 => 90 , 
		name2 => 30 ,
		name3 => 99 
	    }
	    
	}
	
    }
    );


my @all_insts = keys %hash;

my @all_deps;
foreach my $single_inst ( @all_insts ) { 

    push @all_deps, keys %{ $hash{ $single_inst } };

}

my @all_roll_nos;
foreach my $single_inst ( @all_insts ) { 

    foreach my $single_dep ( @all_deps ) { 

	push @all_roll_nos, keys %{ $hash{ $single_inst }->{ $single_dep } };

    }

}

my @all_names;
foreach my $single_inst ( @all_insts ) { 

    foreach my $single_dep ( @all_deps ) { 

	foreach my $single_roll_no ( @all_roll_nos ) { 

	    push @all_names, keys %{ $hash{ $single_inst }->{ $single_dep }->{ $single_roll_no } };

	}

    }
	
}

    
my @all_marks ;
foreach my $single_inst ( @all_insts ) { 

    foreach my $single_dep ( @all_deps ) { 

	foreach my $single_roll_no ( @all_roll_nos ) { 

	    foreach my $single_name ( @all_names ) {
		push @all_marks, $hash{ $single_inst }->{ $single_dep }->{ $single_roll_no }->{ $single_name };
	    }
	    
	}
	
    }
    
}

my @sorted_marks = sort( { $a <=> $b } @all_marks );

dump( @sorted_marks );