#!/usr/bin/perl

use strict;
use warnings;

while (my $txt = <DATA>) {
    chomp($txt);
    next unless my ($term) = ($txt =~ m/.+=(.+)$/);
    my $result = eval($term);
    print "$txt=$result\n";
}

sub POT {
    return $_[0]**2;
}
sub SQRT {
    return sqrt($_[0]);
}

__DATA__
ABC=1+1
Z=SQRT(POT(320)+POT(200))