TOPEKA — Two men who were part of a drug- trafficking operation that sold methamphetamine in Great Bend, Topeka and Kansas City, Kan., have pleaded guilty, U.S. Attorney Barry Grissom said Thursday. Adan Molina, 30, Great Bend, and Alfonso Rubio-Ayala, 27, Topeka, each pleaded guilty to one count of conspiracy to distribute methamphetamine. Molina and Rubio-Ayala entered guilty pleas after three days of trial in U.S. District Court in Topeka.