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