I am designing an educational toy to teach children the alphabet, i need a circuit for this. with 20 Buttons, 1 switch, 1 buzzer, 2 Green LED's and 1 Red LED. one green LED is a power light. When a button is pressed on the left or right, a button in the middle with the same letter will have to be pressed for the green LED to come on and a buzzer will come on only when the Red LED is lit because its the wrong button pressed, the green LED will come on when the correct button is pressed. buttons on the left go from A to E and the buttons on the right go from F to J, the buttons in the middle are the same but have a picture of something for instance, an apple. so when the button A is pressed, the button with Apple next to will have to be pressed for the Green LED to come on, but if a different button is pressed, a Red LED with a buzzer will come on. i have a drawing but i cant seem to get it on here. 
