Best way to pay off my mortgage

Pritch2003

Hi, I am moving house and will have a 50k mortgage on a 250k house. 

My question, what's the best option to get it paid off in 5 years?

Do I get a 5 year or a 25 year mortgage, fixed for 5 years, unlimited/limited overpayment? No early redemption fees?

I struggle with the numbers.

Is anyone confident in what they think would end up being the cheapest way to pay it off over the 5 years?

For the sake of the exercise please assume I can afford repayments and I'm young enough to get a long mortgage term etc. It's just the maths and percentages that I'm struggling to get my head around

Thanks for any help 🙏