SMN(A) is the mint mark for Nicomedia. It also says on the sides: "GLORIA EXERCITVS". Theoretically, you can already identify the coin with this.
On the front you can see something with "CONSTAN....". So it could be Constans or Constantius.
It should be one of the following coins.
Here are the links:
N#351944
N#104637
N#43103
However, if the reverse says SMKΔ, then it is this coin:
N#75966
or this one:
N#50035
Referee for coins from Roman provinces, Western/ Eastern Roman Empire, Roman Imperial usurpations