Pisano period

The Pisano period refers to the repeating cycle of the last digits of Fibonacci numbers when divided by a specific number, called the modulus. In other words, if you take Fibonacci numbers and look only at their remainders when divided by this number, you'll notice that these remainders follow a pattern that repeats after a certain length. This cycle length is known as the Pisano period. Understanding this helps in efficiently calculating Fibonacci numbers modulo a number, especially for large indices, and has applications in computer science and cryptography.