Print three maps in columns on console? c++

so basically i have three maps as mapone, maptwo and mapthree. all three contain student names and and their marks. first map contains computer students, second one contains medical students and the third one contains commerce students. i know i have to use library and setw. what i dont get it how do i iterate through all three at the same time to print them together.. can anyone help? thank you! i want it to be printed on the console as: COMPUTER MEDICAL COMMERCE joey 45 ed 20 harold 50 malisa 36 jane 60 aron 70 emily 60 judy 70 barney 45