 Complete the following phrase:  The Liga Comunista 23 de Septiembre , or LC23S, was a Marxist-Leninist urban guerrilla movement that emerged in Mexico in the early 1970s. The result of the merging of various armed revolutionary organizations active in Mexico prior to 1974, with the objective of creating a united front to combat the Mexican government; the name was chosen to commemorate an unsuccessful guerrilla assault on the barracks of Ciudad Madera in the northern state of Chihuahua led by former schoolteacher Arturo Gámiz and the Peoples Guerrilla Group on September 23, 1965. The LC23S militancy was made up mainly of young disenfranchised university students who saw any opportunity of a peaceful political transformation die in the aftermath of the 