# 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}}}
{12,11,10,9,8,7,6,5,4,3,2,1,0}
# 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
{{}{{}{{}{{}{{}{}}}}}}
{10,9,8,7,6,5,4,3,2,1,0}
# Test case 5 - left-branch tree
{{{{{{}{}}{}}{}}{}}{}}
{10,9,8,7,6,5,4,3,2,1,0}
