Answer
The reading on the ammeter decreases.
Work Step by Step
When one strip is cut, the equivalent resistance of the strips increases. Previously, three identical resistances were in parallel ($R_{eq}=\frac{R}{3}$), and now there are only two in parallel ($R_{eq}=\frac{R}{2}$).
The resistance increases, so the current in the circuit decreases. The reading on the ammeter decreases.