Am i eating well..?! Or i need to eat more..?

I'm 16, 5'4" and 35 kgs only! I eat 2 breads, one gl of milk and an egg at morning, one cup of rice at noon with fish, one plate of potatoes and one gl of milk in afternoon and one cup of rice at night. Still i can't put on weight.. I don't do any physical work but i do lotz of brain work. Should i add something in my diet..?! How much calories um taking daily and how much i need to gain weight...?