wiring the escap 16 to the adafruit shield.

The escap 16 motor has 6 pins from the encoder, one for Vcc, one for ground, one for motor+, one for motor-, one for A and one for B. I have an adafruit stepper that has only 5 pins, + and - for A and B, plus ground, with a VIn (is that the same as VCC?) elsewhere. What should be the best arrangement?