Given: Set of Set of Intervals. Example {{[1,2], [3,4]}, {[1, 3]}, {[13,14]}} Wanted Result: Largest Subset, in which no Interval overlaps with another from every Set pairwise. Example: <pre> Input {{[1,2], [3,4]}, {[1, 3]}, {[13,14]}} A possible Solution would be: {{[1,2], [3,4]}, {[13,14]}} Another could be {{[1, 3]}, {[13,14]}}, it's not important that the solution above has more 'subelements', its only important that 2 = |{{[1,2], [3,4]}, {[13,14]}}| = |{{[1, 3]}, {[13,14]}}| </pre> Now i am looking for a good/efficient Algorithm to solve that problem.