my $johndoe_hours = 0;
foreach my $month ( keys %main } {
   $johndoe_hours += $johndoe_hours + $main{$month}{johndoe};
}


##</code><code>##


my $johndoe_hours = 0;
foreach my $month ( keys %main } {
   $johndoe_hours += $main{$month}{johndoe};
}


##</code><code>##

my $johndoe_hours = 0;
foreach my $month ( keys %main } {
   if ( exists $main{$month}{johndoe} ) {
   $johndoe_hours += $johndoe_hours + $main{$month}{johndoe};
   }
}


##</code><code>##

my $johndoe_hours = 0;
foreach my $month ( keys %main } {
   if ( exists $main{$month}{johndoe} ) {
   $johndoe_hours += $main{$month}{johndoe};
   }
}