Simplest way to compare to faces (face recognition)

hello,

i was asked to make a code to recognize faces in images, i have to use matlab which i'm not good at it

so i hope you help or give me a hint

i did some research and found some codes but it didn't accomplish my goal

i converted RGB to gray then extracted face from it

and i have a file contains 100 faces (dataset)

each 10 images for one person

now i need to search this 100 faces for input face

i have no idea of how to compare to faces