Waiting for first coin flip

You'll start by simulating a series of coin flips, and "waiting" for the first heads.

This exercise is part of the course

Foundations of Probability in R

Simulate 100 instances of flipping a single coin with a 20% chance of heads, and save it as the variable flips. (Thus, flips should be a vector of length 100).
Use which() to find the first case where a coin resulted in heads.

Have a go at this exercise by completing this sample code.

# Simulate 100 instances of flipping a 20% coin
flips <- ___

# Use which to find the first case of 1 ("heads")
which(___)[1]