# Test case 1 - single node
{a}
{0}
# Test case 2 - standard tree
{a{b{c}{d{e}}}{f{g}{h{i{j}{k}}}}{l{m}}}
{2,4,3,1,6,9,10,8,7,5,12,11,0}
# Test case 3 - a path
{{{{{{{{{{{{{{{{{{{{}}}}}}}}}}}}}}}}}}}}
{19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0}
# Test case 4 - right-branch tree
{{}{{}{{}{{}{{}{}}}}}}
{1,3,5,7,9,10,8,6,4,2,0}
# Test case 5 - left-branch tree
{{{{{{}{}}{}}{}}{}}{}}
{5,6,4,7,3,8,2,9,1,10,0}
#
{{a}{b{c}}}
{1,3,2,0}