KöMaL 2011 C1085
There are coins on the table, with their tails side facing upwards. In each step, -1 coins are turned over. Is it possible to achieve that all coins have heads facing upwards?
Official text KöMaL. Quoted with source.
Solutions
No solution is on olymmath yet. Official and human solutions come first when they arrive. AI solutions come after them, with a label.
Similar problems
These problems have the most words in common with this statement.