use strict;
print "what is the value of i:";
chomp(my $i=<>);
print"\n";
print "what is the value of j:";
chomp(my $j = <>);
print "\n";
my $ackerman = &ackerman($i,$j);
print "A($i,$j) = $ackerman\n";
sub ackerman{
my $i=shift;
my $j = shift;
if($i == 1){
undef $i;
return 2**$j;
}
elsif($j==1){
undef $j;
return &ackerman($i-1,2);
}
else{
return &ackerman($i-1,&ackerman($i,$j-1));
} 
}