If you look around, you will find this sort of question asked frequently, just substitute the countries a little.
The general answer is we don't know your spending style, and what you will be buying. But I can say we spent 2 weeks on a land tour in Europe (Amsterdam, and various stops in France), and we spent less than 80 euros in cash. We ate out twice a day, stayed in hotels, took buses, trains and a couple taxis.
In other words, you need very little cash. Certainly no more than 100 euros.