I am wondering if anyone can help me with this simple problem. My electronics class had a lab test with this question: Construct a circuit using 5 nopb switches, 3 incandescent 12v lamps, and as few diodes to do the following: pressing switch 1 turns on lamp 1, switch 2 lamp 2, switch 3 lamp 3, switch 4 lamps 1 and 3, and switch 5 all lamps. Seems pretty simple huh. The least diodes I could come up with and work was 4. Just wondering if anyone could do it with less. Any help would be greatly appreciated.