100 Women: Can women change the world in a week?
The BBC's award-winning 100 Women news season is breaking new ground.
The annual series - which shines a light at issues affecting women all over the world - is this year giving women a chance to make a change.
Seemingly endless stories of harassment, inequality, and simply less visibility in many spheres of society, can feel depressing and disempowering.
So we are asking the women in this year's season to create innovations to tackle some of these inequalities.
Now in its fifth year, 100 Women will be looking at four issues: the glass ceiling, female illiteracy, street harassment and sexism in sport.
Women with specialist interest or experience will work together in four different cities in the four weeks of October to make an innovation that will aim to help people affected by these problems.
If 100 Women is to succeed in the challenge, it will be because women around the world have helped shape the understanding of how and why these problems matter.
Because they've shared a great idea that they've seen. Or because they've come up with something themselves.
It's not just about ideas either - 100 Women will have conversations on radio, online and on social media.
The glass ceiling challenge is based in San Francisco, the female illiteracy challenge is based in Delhi, the street harassment challenge is based in London with help from a team in Nairobi, and the sexism in sport is based in Rio - but the conversation has to be global and we want to hear from women all over the world.
100 Women wouldn't be complete without its list of women who've done something different to change the world.
And because this year we've reinvented the season, 100 Women also thought we should reinvent the list as well.
When the names are announced later this month, there will only be 60 women on the list. The other 40 spaces will remain open, and as the season progress, we'll be adding women who have taken up the challenge in some way.
"In 2015, women hosted 150 debates in 10 languages and 30 countries, in 2016, people added 450 deserving but over-looked women to Wikipedia, and now in 2017 we're taking it to a whole new level of participation," says 100 Women editor Fiona Crack.
"It's going to be exciting but nerve-racking to see what these talented 100 will come up with and if they can pull it off in a month."
We've got some inspiration to get started, with a look at nine things you may not have realised were invented by a woman.
And a look at some of the global solutions people have come up with already, to tackle health and safety problems facing women.