To the east.
Use Fleming's left hand rule.
FLHR can be used to analyse current carrying conductors or charged particles moving through magnetic fields.
An electron is negatively charged and moving downwards, so point the second finger upwards. The magnetic field is north to south, so point the index finger horizontally away from you (that direction is south then). Lastly see in which direction the thumb points, this is the direction the force on the electron acts and as such it is the direction in which the electron will be deflected. The direction is to the east.