$2^{-4} \ 2^{36} \mod 37 = 2^{-4} \mod 37$ (By Fermat’s Little Theorem)

Since, $2 \times 19 \equiv 1 \mod 37. \ $ So, $2^{-1} \mod 37 = 19$

Hence, $2^{-4} \mod 37 = 19^4 \mod 37 = 7$

Since, $2 \times 19 \equiv 1 \mod 37. \ $ So, $2^{-1} \mod 37 = 19$

Hence, $2^{-4} \mod 37 = 19^4 \mod 37 = 7$