The Congress, on a roll after sealing seat sharing deals with Arvind Kejriwal's Aam Aadmi Party and Akhilesh Yadav's Samajwadi Party, is aiming for a hat-trick, with a new formula for Mamata Banerjee. Sources said the party is hoping to get five of Bengal's 42 seats. The downside - as in deals with AAP and SP -- the Congress may have to part with seats in states where it is the main Opposition. This could involve two seats in Assam and one in Meghalaya.