This is my solution to a problem from the USACO 2020 December Contest.
Farmer John's cows play a number game during an online meeting. Elsie gives Bessie seven integers, representing A, B, C, A+B, B+C, C+A, and A+B+C in some order. The task is to determine and print the values of A, B, and C. The input is seven space-separated integers, and the output should be A, B, and C separated by spaces. The solution is unique.
For example, one possible input is "2 2 11 4 9 7 9," and the corresponding output is "2 2 7."