3n-4(dml dmc dmc dmr)-1mc-2st

Any ideas?:(

Doesn't matter. Illegal formation.
''At least 4 players on the opponents side of the pitch.''

4-4-2 classic might work.

finally i played 3-1-4-2.the score 0-0.i had possesion 80-20.What about the illegal formation?

You will have 80% possession if your opponent uses an illegal formation. This means a win almost every time. You just had bad luck.