Leftwards arrow
On Windows, hold Alt and type 27 on the number pad, then let go of Alt.
Copy it
About the leftwards arrow
The first version of ASCII, published in 1963, had a left arrow where the underscore _ sits today. The two codes were later reassigned, and the arrow disappeared from computer keyboards.
Its best-known job in programming is assignment: APL and Smalltalk both write x ← 5 to mean “x becomes 5”, and textbook pseudocode often does the same.