Add Advertisement Blocks into Wordpress Pravda Premium Theme

Current Wordpress theme is : Pravda Theme Demo : [login to view URL] What is the requirement ? After every 1st row which means after every 3 posts on homepage I need 3 blocks on homepage for advertisement (to show google ads) - size of blocks should be 340 * 300 so they fit google adsense ads , to be more clear after every 3 posts on homepage and I need 3 blocks where I can show 3 advertisement in 3 blocks , after these 2 rows the remaining posts should come up . To be simplier 1st row – 3 posts 2nd - 3 ad blocks 3rd 3 remaining posts on homepage 4th again 3 ad blocks 5th row 3 remaining posts on homepage and this goes on . What I don’t want ? No posts should duplicate or reappear after final deliverables. Demo : The advertisement block is in 2nd row – 4th item which can be seen in below link . this as simple demo to show ads on home page block. [login to view URL] . I need these ad blocks after every 3 posts alternatively. Hope that’s clear.