CSS floating div takes no width space

I have a very, i think basic, question regarding CSS with floating div objects.

i have 5 divs Div1, Div2, 开发者_开发问答Div3, Div4 and Div5 and what i am trying to do is the following

1. Div1 float to left
2. Div2, 3, 4, 5 float to the right (in the same order, so will have Div2 displayed at the very right)
3. have Div3 overlay on top of Div2 4 Div4 and Div5 would shift accordingly

but I am having a trouble positioning Div4 and Div5 right beside Div2 because the Div3 is still take it's place so it leaves a big white space in btw.

any suggestion?

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Is this what you're looking for? Or maybe this?