US election 2016: How to win the presidential nomination

Before Americans decide who to pick for president in November's election, the political parties must first choose a nominee.

It's a complex process which starts with the Iowa caucuses on 1 February but can end up taking months, as the BBC's Katty Kay explains.

Check out all our election coverage at bbc.com/us2016.

Produced by the BBC's Mat Morrison, edited by Franz Strasser.