The travelling salesman problem is classified as NP-hard and it is one of the most notorious problems in the class.
The task is to find the cheapest closed path connecting n=74 balloons, with well-defined costs for the transfer between any two pairs of balloons, and exact your revenge on them. (The tasks where the balloons explode and where they don't are equivalent.)
However a dog called Prof Simon, not to be confused with Jim Simons, has solved the problem for n=74 in t=47 seconds. Congratulations. ;-)