by @Sakib Fork
 
id_53fb599a_7158_4709_b440_c16e2e7806aa Begin id_583b2f24_e36e_43e4_9e20_22be7c1175c3 x = readInput() id_53fb599a_7158_4709_b440_c16e2e7806aa:s->id_583b2f24_e36e_43e4_9e20_22be7c1175c3:n id_4bcdcc77_09ff_467c_b0b0_795ad03ff018 y = readInput() id_583b2f24_e36e_43e4_9e20_22be7c1175c3:s->id_4bcdcc77_09ff_467c_b0b0_795ad03ff018:n id_37e3ff83_d27c_452c_afbe_f89843141e70 x > y id_4bcdcc77_09ff_467c_b0b0_795ad03ff018:s->id_37e3ff83_d27c_452c_afbe_f89843141e70:n true_dummy_up_id_37e3ff83_d27c_452c_afbe_f89843141e70 id_37e3ff83_d27c_452c_afbe_f89843141e70:e->true_dummy_up_id_37e3ff83_d27c_452c_afbe_f89843141e70 true false_dummy_up_id_37e3ff83_d27c_452c_afbe_f89843141e70 id_37e3ff83_d27c_452c_afbe_f89843141e70:w->false_dummy_up_id_37e3ff83_d27c_452c_afbe_f89843141e70 false id_35c60115_ea64_44a9_a4c1_deb1ddb73877 diff = x - y true_dummy_up_id_37e3ff83_d27c_452c_afbe_f89843141e70->id_35c60115_ea64_44a9_a4c1_deb1ddb73877:n id_29ceb619_2042_4d3c_84f9_0a2ad6120635 sum = x + y false_dummy_up_id_37e3ff83_d27c_452c_afbe_f89843141e70->id_29ceb619_2042_4d3c_84f9_0a2ad6120635:n id_eb10da36_42a2_49fd_aa2f_55c1511c35d1 diff id_35c60115_ea64_44a9_a4c1_deb1ddb73877:s->id_eb10da36_42a2_49fd_aa2f_55c1511c35d1:n true_dummy_down_id_37e3ff83_d27c_452c_afbe_f89843141e70 id_eb10da36_42a2_49fd_aa2f_55c1511c35d1:s->true_dummy_down_id_37e3ff83_d27c_452c_afbe_f89843141e70:n id_61e8187a_a3bd_4de9_95f4_6ce28f06b5b1 sum id_29ceb619_2042_4d3c_84f9_0a2ad6120635:s->id_61e8187a_a3bd_4de9_95f4_6ce28f06b5b1:n false_dummy_down_id_37e3ff83_d27c_452c_afbe_f89843141e70 id_61e8187a_a3bd_4de9_95f4_6ce28f06b5b1:s->false_dummy_down_id_37e3ff83_d27c_452c_afbe_f89843141e70:n end_id_37e3ff83_d27c_452c_afbe_f89843141e70 true_dummy_down_id_37e3ff83_d27c_452c_afbe_f89843141e70->end_id_37e3ff83_d27c_452c_afbe_f89843141e70 false_dummy_down_id_37e3ff83_d27c_452c_afbe_f89843141e70->end_id_37e3ff83_d27c_452c_afbe_f89843141e70 id_001116e3_ec93_4347_bd68_a980a4baa78d End end_id_37e3ff83_d27c_452c_afbe_f89843141e70:s->id_001116e3_ec93_4347_bd68_a980a4baa78d:n
<?php
$x = readline();
$y = readline();
if ($x > $y) {
  $diff = $x - $y;
  print($diff);
} else {
  $sum = $x + $y;
  print($sum);
}
?>