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