... malicious adversary We say a person is safe if he never gets wet There exists a trivial safe strategy: Always carry an umbrella However, carrying an umbrella in sunny days is annoying As an alternative, ... the total number of umbrellas in G Consider an on- line game between a player and the adversary, assuming that u(G) is fixed in advance Game Carrying- Umbrellas(G, u(G)) Initialization Player determines ... this paper, we assume G is connected and simple J.-H Lee et al., Carrying Umbrellas, JGAA, 5(5) 3–16 (2001) 1.3 Related works Every online problem can be viewed as a game between an online algorithm...