n python Character user$\_$char is read from input. Write a while loop that reads characters from input until character $\text{'}$s$\text{'}$ is read. In each iteration: Update sum$\_$chars with the sum of sum$\_$chars and $1.$ Then, read the next character from input into variable user$\_$char. Character $\text{'}$s$\text{'}$ should not be included in the count.