answers: fourth
context: the eighth episodes of the first season of "The Flash" and the third season of "Arrow" formed a two-part event known as "Flash vs. Arrow". In January 2015, The CW president Mark Pedowitz said that there would be an Arrowverse crossover every season. In the 2015–16 television season, a two-part event between the eighth episodes of the second season of "The Flash" and the fourth season of "The Arrow" was used to set up a new team-up series, "Legends of Tomorrow". For the 2016–17 television season, the "Invasion!" crossover included "The Flash", "Arrow", and "Legends of Tomorrow", with the event </s> captures the JLA and JSA and forces them to help recover mystical artifacts that were lost when the Justice League Satellite was destroyed. These artifacts will allow Mordru to raise the Demons Three as his servants. The two teams are sent to the 30th Century, where they meet the Legion of Super-Heroes. The stories can be found in "Justice League of America" #147 and 148 (October and November 1977). The JLA and JSA fight the Black Pirate, Enemy Ace, Jonah Hex, Miss Liberty, and the Viking Prince, who have been taken from their times and given superpowers by the Lord </s> of Us Must Die!")<br> "Justice League of America" #113 (September–October 1974) - ("The Creature in the Velvet Cage!")<br> "Justice League of America" #123 (October 1975) - ("Where on Earth Am I?")<br> "Justice League of America" #124 (November 1975) - ("Avenging Ghosts of the Justice Society!) After a teleportation accident, the JLA and JSA must help the Freedom Fighters fight the Nazis on Earth-X, where the war never ended, who have used a machine to take over people's minds. The stories can be found in "Justice League of America" #107 and #108 published in 1973. The story in #108 is called
question: what season is crisis on earth x part 1