Solve the programming task below in a Python markdown code block.
# Introduction

The first century spans from the **year 1** *up to* and **including the year 100**, **The second** - *from the year 101 up to and including the year 200*, etc.

# Task : 
Given a year, return the century it is in.
Also feel free to reuse/extend the following starter code:
```python
def century(year):
```