How many levels of nesting are there in this design?

X is an integer test score between 0 and 100.

input X

if (0 <= X and X < 49)

output "you fail"

else if (50 <= X and X < 70)

output "your grade is" X

output "you did OK"

else if (70 <= X and X < 85)

output "your grade is" X

output "you did well"

else if (85 <= X and X < 100)

output "your grade is" X

output "you did great"

endif

output "how did you do?"