Please summarize the first act of Arms and the Man by George Bernard Shaw.

Shaw's 1894 Arms and the Man is set near the end of the short war between Serbia and Bulgaria in 1885. As Raina, a rich young Bulgarian woman stands on her balcony, filled with romantic thoughts, her mother appears to tell her the Bulgarians have won a "great victory," led by Sergius, Raina's betrothed. Raina is delighted that Sergius is a hero and says it proves all her ideals about the war are right after...

Shaw's 1894 Arms and the Man is set near the end of the short war between Serbia and Bulgaria in 1885. As Raina, a rich young Bulgarian woman stands on her balcony, filled with romantic thoughts, her mother appears to tell her the Bulgarians have won a "great victory," led by Sergius, Raina's betrothed. Raina is delighted that Sergius is a hero and says it proves all her ideals about the war are right after all. She had been worrying that all her romantic war thoughts came from reading Byron and Pushkin, but this turn of events, she thinks, shows that her ideas are legitimate. 

After her mother leaves her and Raina has blown out her candle to go to bed, a young soldier from the Serbian side appears in the darkness, demanding her help. When she lights a match, she sees he looks "deplorable," and he tells her that he has deserted from the army. She thinks he is a coward and is further angered when he tells her that Sergius is not hero, but won his battle undeservedly and by accident. Captain Bluntschli, the deserting soldier, calls Sergius "Don Quixote," tilting at windmills, and says only the accident of the Serbians having ordered the wrong size cartridges for their guns saved his cavalry from being mowed down in what should have been a disaster.

Raina's sympathy for the soldier grows despite herself and despite the way he upsets her ideals. She tries to order him back down the water pipe he climbed to get into her room to escape the troops chasing him. However, he is so tired and the feat so dangerous that she leaves him in her room, where he quickly falls asleep. Raina gets her mother, but they cannot rouse him.