reached depth = 3
reached depth = 2
reached depth = 1
reached depth = 0
after 1st iter: {'_for' => {0 => {'_recr' => {'_for' => {0 => {'_recr' => {'_for' => {0 => {'_recr' => {'s' => 0}, 't' => 2}}, 's' => 2}, 't' => 4}}, 's' => 4}, 't' => 6}}, 's' => 6}
reached depth = 3
reached depth = 2
reached depth = 1
reached depth = 0
after 2nd iter: {'_for' => {0 => {'_recr' => {'_for' => {0 => {'_recr' => {'_for' => {0 => {'_recr' => {'s' => 0}, 't' => 4}}, 's' => 4}, 't' => 8}}, 's' => 8}, 't' => 12}}, 's' => 12}
reached depth = 3
reached depth = 2
reached depth = 1
reached depth = 0
after 3rd iter: {'_for' => {0 => {'_recr' => {'_for' => {0 => {'_recr' => {'_for' => {0 => {'_recr' => {'s' => 0}, 't' => 8}}, 's' => 8}, 't' => 16}}, 's' => 16}, 't' => 24}}, 's' => 24}
