No Seven! - Merge Numbers

This is a rather simple and relaxing puzzle game.
All you need to do is to find suitable numbers that can sum up to 7,
Then make them in a line.

Boom!

Those numbers disappear.

Keep to do it this way and see how far you can go.

Rules:
Drag numbers from bottom and put them into the center zone;
If some numbers in a line can sum up to 7, they will vanish;
7 can only be removed when 3 of them are put in a line.

Take it and enjoy.