cicada | Favorite article collections system | Runtime Evironment library

I'm an 8th grader who got this assignment a couple days ago, if anyone needs an explanation as to why it's so easy.

Introduction

As described in BBC's The Code and Planet Earth, Periodical Cicadas go into hibernation for years at a time. They emerge all together as a species at the same time, when they have safety in numbers to feed and start a new generation of cicadas.

But different species of cicada have different hibernation periods. For this challenge, let's say the Red Cicada has a regular hibernation period of 17 years, while the Yellow Cicada has a regular hibernation period of 13 years. (You might notice that these are prime numbers. It works to minimise the chance of the Red and Yellow Cicadas both emerging in the same year, when they would have to compete for the same food.)

Now, here's your challenge: We know that the Red Cicada last emerged in 2005, and it has a hibernation period of 17 years. We also know that the Yellow Cicada last emerged in 2011, and it has a hibernation period of 13 years.

Your job is to model the next 1000 years to figure out which years will have a rare clash. Your solution needs to list the specific years between now and 3020 when both species emerge together in the same year.

I don't want the answer to my question, I could do that by hand. I've got a little bit of the code down, but i need it to repeat until 3020 and outline any crashes

here's what i've got so far:

Both links with following anchor-ed a tags: