You are totally free to wear whatever kind of shoes you want. The style of shoes that women were here may be different than our style but it is just a fashion thing, no rules.

But just have in mind that the AC in the offices is often working with maximum power and if you are a cold hand/feet person you will dream of closed toe shoes (personally I was dreaming of woolen socks:-) and it was in June!!!

Just bring a little of both and do not worry you can find shops here to complete your collection (Nine West...)